Class XI Biology Notes first year sindh board

Biology

Sindh Text Book Board, Jamshoro.

INTERMEDIATE STAGE BIOLOGY BOOK ONE

FOR CLASS XI

For

Sindh Textbook Board, Jamshoro.

Book arranged by www.mynoteslibrary.com

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CONTENTS SECTION

1

INTRODUCTION

CHAPTER

1

THE BIOLOGY

SECTION

2

UNITY OF LIFE

CHAPTER

2

BIOLOGICAL MOLECULES

6

CHAPTER

3

ENZYMES

11

CHAPTER

4

THE CELL

15

SECTION

3

BIODIVERSITY

CHAPTER

5

VARIETY OF LIFE

21

CHAPTER

6

THE KINGDOM PROKARYOTAE

25

CHAPTER

7

THE KINGDOM PROTISTA

31

CHAPTER

8

THE KINGDOM FUNGI

35

CHAPTER

9

THE KINGDOM PLANTAE

47

CHAPTER

10

THE KINGDOM ANIMALIA

56

SECTION

4

FUNCTIONAL BIOLOGY

CHAPTER

11

BIO-ENEGETICS

71

CHAPTER

11

NUTRITION

75

CHAPTER

12

GASEOUS EXCHANGE

84

CHAPTER

13

TRANSPORT

94


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Chapter 1 INTRODUCTION BIOLOGY: Biology is one of the natural sciences which deals with the study of living organisms. It is known as study of life. The word biology is derived from Greek words Bios means life and logos mean study or knowledge. Formerly living organisms were classified into two kingdoms: 1. PLANT KINGDOM: In this kingdom plants were included. The study of plants is called Botany. 2. ANIMAL KINGDOM: In this kingdom animals were included. The study of animals is known as zoology. BRANCHES OR FIELDS OF SPECIALIZATION OF BIOLOGY: Some major branches or fields of specialization in biology are as follows: 1. MOLECULAR BIOLOGY: It is a new and modern branch of biology in which s tructure and function of those. Molecules are studied that help in biological processes of living organisms, such as nucleic ac id, gene structure, it's function protein and protein-synthesis. It is the foundation of genetic engineering. 2. MICROBIOLOGY M ICROBIOLOGY:: It deals with the study of microorganisms, such as viruses, bacteria, protozoans etc. 3. ENVIRONMENT BIOLOGY: It deals with the study of environment and its effect on the body of organisms. 4. MARINE BIOLOGY: It deals with the study of living organisms which are found in sea water or ocean water. It also deals with the physical and chemical characteristics of their environment. 5. FRESH WATER: It deals with the study of life found in fresh water like rivers, lakes, ponds streams etc. with physical and c hemical characteristics of living organisms affecting the life. 6. PARASITOLOGY: PARASITOLOGY: It deals with the study of the parasitic living organisms, their life cycle, method of disease transmission and interaction with their hosts. 7. HUMAN BIOLOGY:


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It includes all aspects of human life such as anatomy, physiology, health, inheritance, evolution etc. 8. SOCIAL BIOLOGY: It deals with the study of social activities of certain animals within a population, specially human beings. 9. BIOCHEMISTRY: It is a very modern and recent branch of biology. It deals with the study of the (i) use of data and techniques of engineering; and (ii) technology for the study and solutions of problems related with living organisms specially in human beings. HYDROPONICS: It is the soil less or water culture technique, in which terrestrial plants are grown in aerated solution. By this technique vegetables and other plants can be grown. It helps to fulfill the food requirement of people of a particular area. Tomato crop and other vegetables crops are grown in green houses through this technique and satisfactory production is obtained. ADVANTAGES OF HYDROPONICS:

By using this technique the crop can be protected from soil diseases and weeds. In dry parts of the world some crops can be grown successfully, for example in green houses tomato and other crops are grown to get production.

BIOLOGICAL METHOD: The method used in the study biological work is called biological method. It is based on the same principles which are applied in other fields of science. During the research in biology various topics are selected and they are explained in a simple manner which can be easily understood. In order to carryout the research many steps are followed in a systematic way. Scientists make deep observations and collect all informations about the work, which have been reported by others. On the basis of these facts and informations a scientist presents an experimental statement, called hypothesis. This hypothesis can guide further observations and experimentations. APPLICATIONS OF BIOLOGY: IMMUNIZATION: Immunization i.e. resistance against diseases is carried out by vaccination throughout the world. As a result of this technique polio, small pox, hepatitis and other dangerous diseases have been controlled and rate of infection and death o f infants is greatly reduced in the whole world. ANTIBIOTICS:


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Antibiotics are substances which are used to prevent the growth of microorganisms. First antibiotics penicillin was isolated from a fungus, called penicillium notatum. This great work was done by Fleming, flory and chain, they got nobel prize. These antibiotics are widely used to control many diseases, such as T.B., cholera, leprosy, anthrax diseases have been controlled properly in the whole world. CHEMOTHERAPY: Biology always tries to develop new medicines for the cure and treatment of diseases. In recent days some harmful diseases like aids, cancer are treated with certain chemicals, this technique is called c hemotherapy. RADIOTHERAPY: Use of radioactive rays (X-rays) are also widely used in the treatment of diseases. This technique is called radiotherapy. This technique is also useful for the diagnosis of diseases. Radiotherapy is usually used for the treatment of cancer, but this technique is very expensive and painful. FOOD SHORTAGE DUE TO POPULATION INCREASE: Due to population increase there is always shortage of food and other necessary things. By the help of modern technology in agriculture and other related fields production of food can be increased. CLONING: It is a modern technique in biological science by which duplicate copies of genetics material are produced. It is a method of asexual reproduction. All members produced by cloning are genetically identical. The examples of cloning are regeneration, asexual reproduction in animals and plants. Twins in man and tumors of cancer. In 1997 scientists in Scotland produced a sheep "Dolly" by cloning. This technique is successfully applied in lower mammals. PROCEDURE OF CLONING: In the process of cloning the nucleus of an egg is removed. Then a nucleus from a cell of fully developed individual is taken and introduced into that egg. After that this changed egg is implanted into the womb of female for complete development. The individual which is developed by this process in quite similar to that individual whose nucleus is used. IMPORTANCE OF CLONING: 1. By cloning method different kinds of human cells can be prepared, such as liver cells, skin cells, blood cells etc. In this way it may be possible to develop body organs of human being and defective organs may be replaced by cloned organs. 2. This technique can be used to improve the quality in agriculture and medical sciences. 3. Growth hormones, insulin and other substances can be prepared by cloning method.


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Chapter 2 BIOLOGICAL MOLECULES

BIOLOGICAL IMPORTANT PROPERTIES OF WATER: The biologically important properties of water are as follows: 1. BEST SOLVENT: It is the best solvent for many substances. All the important processes occur in the presence of water. 2. HIGH HEAT CAPACITY: Water is slow to absorb and release heat. The specific heat capacity of water is high. It needs more heat to warm it up. 3. HIGH HEAT OF VAPOURIZATION: Water requires higher amount of heat energy to change into vapours, so water molecules remain in stable form. 4. AN ATMOSPHERIC MOLECULE: Water acts both an acid and a base, so it is an atmospheric molecule. In acidic condition it gives up electrons to form H+ ions and as base it gains electrons to form OH- ions. 5. COHESIVE FORCE IN WATER MOLECULES: There is a force of attraction among the water molecules, it is called cohesive force i.e. the water molecules remain together due to hydrogen bonding and not disturbed, so it helps in the transportation of substances both outside and inside the cells. PROTEINS: Proteins are the complex organic compounds. They consist of carbon, hydrogen, oxygen, nitrogen, sulphur and sometimes phosphorus. They are formed by the combination of amino acids. The amino acids are of twenty types, so different proteins may be formed by the linkage of amino acids. When amino acids are attached together, a polypeptide chain is formed. STRUCTURE OF PROTEINS: According to the structure of proteins, there are four types: 1. PRIMARY STRUCTURE: When amino acids are arranged in linear manner in a polypeptide chain, it is called primary structure. This protein also contains disulphide (S-S) bond. 2. SECONDARY STRUCTURE:


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When amino acids in a polypeptide chain are arranged in spiral manner, it is called secondary structure of protein. It forms a helix (screwlike) structure. 3. TERTIARY STRUCTURE: When amino acids are present in fold or super fold and shows a three dimensional structure, it is called tertiary structure of protein. 4. QUATERNARY STRUCTURE: When two or more polypeptide chains are combined together to form a largesized molecule, it is called quaternary structure of protein. e.g. Haemoglobin of blood.

FUNCTIONS OF PROTEINS: 1. Proteins form the cell structure and body of an organism. 2. They form seeds and other parts in plants. 3. They produce plasma membrane and other organs in the cell. 4. They produce a certain substance in the body of animals which takes part in the formation of skin, muscles nails and hairs. 5. Haemoglobin of blood also contains protein. 6. Proteins also help in digestion of food, expansion and contraction of muscles and clothing blood. 7. Proteins also prepare enzymes. They are organic catalysts which increase the rate of chemical reaction. 8. Proteins act as hormones, growth factors and gene activators. 9. Proteins also act as antibodies, antigens and fibrine etc.

FUNCTIONS OF CARBOHYDRATES: 1. Carbohydrates produce energy by oxidation, which is used in various functions. 2. Carbohydrates may be changed into other substances. The extra amount of glucose in plants is converted into starch, which can be changed again into glucose at the time of requirement. In animals they are changed into glycogen. 3. The complex carbohydrate molecules form the body of living organisms. They also make the organs strong. Cellulose is also formed from c arbohydrate in plants.

LIPIDS: Lipids are the organic compounds like oil, butter, waxes, fats natural rubber, vitamins A, E and K, steroid such as cholesterol. They are c omposed of carbon,


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hydrogen and oxygen, but oxygen is very less. Lipids are found both in plants and animals. In plants they are usually present in seeds, fruits and nuts. CLASSIFICATION OF LIPIDS: Lipids are divided into following groups: 1. Acylglycerol (fats and oils) 2. Waxes 3. Phospholipids 4. Terpenoids

FUNCTIONS OF LIPIDS: 1. They are the main source of energy. They provide double energy than carbohydrates and proteins. 2. They are the stored energy in the body and can be used at the time of need. 3. They participate in the structural framework of living tissues. They form plasma membrane, membrane of vacuole, mitochondria, nucleus, chloroplast etc. 4. They dissolve vitamins A and D and prevent than from decomposition. 5. They are the component of electron transport system in mitochondria. 6. They are found in the outer cuticle of insects and make them water proof. 7. They form protective covering on the surface of stem, leaf and fruits. 8. Waxes are used in cosmetics, ointments, creams and polish.

DIFFERENCE BETWEEN DNA AND RNA: 1. DNA is composed of two filaments which form a double-helix structure i.e they are linked together like spring. The RNA consists of separate filaments. They do not form double helix. 2. The DNA contains deoxyribose sugar, while RNA has ribose sugar. 3. In DNA a nitrogen base thymine is present, while in RNA the tymine is replaced by Uracil. 4. DNA acts as a genetic material, helps to transfer the hereditary characters, while the RNA takes part in protein-synthesis.

NUCLEOTIDES: These compounds are the sub-units of nucleic acids. In the cells there are three types of nucleotides:


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1. Mononucleotides 2. Dinucleotides 3. Polynucleotides

1. MONONUCLEOTIDES: These nucleotides are found singly in the cell or as a part of other molecules. These nucleotides are not attached to the DNA or RNA. These nucleotides contain additional phosphate groups, for example ATP (adenosine triphosphate) compound contains three phosphates, it is produced from ADP (Adenosine diphosphate), which contains two phosphates. ATP is an energy rich compound. This energy is used in various functions of the body. 2. DINUCLEOTIDES: When two nucleotides are attached to each other by covalent bond, dinucleotide molecule is formed. e.g. NAD (Nicotine amid adenine dinucleotide). The two nucleotides of NAD are attached together by phosphate of one another. 3. POLYNUCLEOTIDES: When many nucleotides are linked together, the compounds are called polynucleotide’s. Nucleic acids are the polynucleotide’s, such as DNA and RNA. The DNA nucleotides are involved to transfer the genetic information into new cells. RNA takes part in protein synthesis. Genetic information is carried out in the form of a code, called genetic code. The nitrogen bases of nucleic acids form different codes by combined function with amino acids. In protein synthesis a particular code is required. According to this code arrangement of amino acids and amount of proteins is controlled.

CONJUGATED MOLECULES: When bio molecules of two different groups are combined together, conjugated molecules are formed. Different types of conjugated molecules are as follows: 1. Glycolipids 2. Glycoproteins (mucoids) 3. Nucleoproteins 4. Lipoproteins

1. GLYCOLIPIDS: When fatty acids and carbohydrates are combined with each other, these are called Glycolipids. These compounds also co ntain nitrogen. These are the derivatives of carbohydrate glycerides. Galactolipids and sulpholipids are found in chloroplasts. Glycolipids are also found in brain, called cerebrosider.


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2. GLYCOPROTEINS (MUCOIDS): When carbohydrates and proteins are joined with each other, Glyco proteins are formed. These are commonly found in animal and plant cells in the form of oligo and polysaccharides. E.g. Albumin of egg, Gonadotrophic hormone. Some amount of Glycoproteins is present in cell membrane. 3. NUCLEOPROTEINS: These are the combination of proteins with nucleic acid of nucleus. These are less acidic and soluble in water.

4. LIPOPROTEINS: When lipids and proteins are linked together, Lipoproteins are formed. e.g. Cholesterol and Lecithin lipids are linked with simple proteins. These compounds take part in the transportation of lipids in blood plasma. The Lipoproteins are found in membrane of endoplasmic reticulum, nuclei and mitochondria. These are also present in sheath of nerves, chloroplast and bacterial membrane.


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Chapter 3 ENZYMES ENZYMES: Enzymes are the organic protieneous substances which catalyse chemical reactions in the living organisms. These are considered as bio-catalysts. They increase the rate of chemical reaction but are not consumed in the process. CHARACTERISTICS OF ENZYMES: i. Enzymes are made up of proteins. They are big molecules with higher molecular weight. ii. They can react with both acidic and alkaline substances due to the presence of proteins. iii. In a biochemical reaction only a small amount of enzyme is required as compared to the substrate. iv. Enzymes are not consumed during the reaction. They remain unaffected and can be used again and again. v. The enzymes catalyse only specific reactions; that is, each individual enzyme is restricted in its catalytic activity to one particular reaction or one group of related chemical reactions. vi. Their activities can be accelerated by certain ions or salts, called activator, such as Ni, Mn, Mg, Cl etc. vii. Some enzymes contain a non-proteineous part, called prosthetic group. STRUCTURE AND COMPOSITION OF ENZYMES: The enzymes are basically proteineous in nature. They have relatively high molecular weight of 40,000 and catalase has a molecular weight of 250,000. Certain enzymes consist only of protein, they are called simple protein enzymes. Many enzymes have an attached non-protein group, they are known as conjugated protein enzymes or holoenzymes. It was proposed by Euler in 1932. The holoenzyme consists of two parts: i. The protein part, called apoenzyme. ii. The non-protein part, called prosthetic group. CLASSIFICATION OF ENZYMES: Enzymes are classified into six classes: 1. Oxido-reductases 2. Transferases 3. Hydrolases 4. Isomerases


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5. Lysases 6. Ligases or synthetases 1. OXIDO-REDUCTASES: These enzymes catalyse the oxidation reduction reactions, e.g. dehydrogenases., oxidases and reductases. In these reactions one substrate is oxidized, acts as hydrogen donor and other substrate is reduced. 2. TRANSFERASES: These enzymes help to transfer one group from one molecule to another. This group may be carbon, aldehyde, ketone, phosphoryl or amino group, which is transferred from one compound to another compound. E.g. kinases, transaminese. 3. HYDROLASES: These enzymes are involved in the hydrolysis of compounds (water adding) or breaking of single bond. E.g. Amylase enzyme hydrolyses carbohydrates, protease hydrolyses proteins into amino acids. 4. ISOMERASES: These enzymes catalyse the conversion of a compound into it's isomer. i.e. isomer compounds are similar in atomic formula but different in structure. e.g. isomerase, apimerase etc. 5. LYSASES: These enzymes catalyse the removal or addition of one group from or to a double bond. E.g. fumarase, aldolase etc. 6. LIGASES OR SYNTHETASES: These enzymes catalyse the formation of different bonds by the combination of two compounds in codensation reaction. In this reaction energy is used from other compounds, such as ATP (Adenosine triphosphate). E.g. DNA-polymerase, Aspargine. FACTORS AFFECTING ENZYME ACTIVITIES: Following factors affect the enzyme activity. 1. Temperature 2. Substrate concentration 3. pH 4. Co-enzyme, activators and inhibitors 5. Water 6. Radiation


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1. TEMPERATURE: Enzymes are sensitive to heat. They loss their activity at high temperature. The enzymes are denatured by heat i.e. they are destroyed. The optimum temperature for most of the enzyme is 30°C to 37°C. At freezing point they become inactive but are not destroyed, at 100°C the enzymes are completely destroyed. 2. SUBSTRATE CONCENTRATION: With the increase of substrate concentration, the rate of r eaction is also increased. The enzyme molecule is much larger than its substrate. When concentration of substrate is low, the active sites on the enzyme molecule may not be occupied, thus the enzyme does not work. When enzyme is saturated with substrate concentration, then the rate o f reaction becomes independent of concentration and further increase in substrate has no effect. 3. pH: Each enzyme has an optimum pH at which the enzyme shows maximum activity. Change in pH can cause loss of its activity. It can be destroyed. When pH scale is shifted to the alkaline or acidic side; it's activity is dropped. The o ptimum pH of pepsin is 1.6 (acidic), while pH of trypsin is 8.2 (alkaline). 4. CO-ENZYMES, ACTIVATORS AND INHIBITORS: Other groups, such as co-enzymes and co-factors increase or decrease the enzyme action. These groups are of three types: CO-ENZYMES: The organic molecule of enzyme is called co-enzyme. Its presence increases the activity of certain enzymes. Without these co-enzymes their activity is stopped. E.g. COA, NAD, FAD etc. ACTIVATORS: Activators are the inorganic substances which increase the activity of enzyme, for example Phosphatase enzyme has Mg+2 as an activator and Zn+2 is the activator of enzyme carbonic anhydrase. INHIBITORS: Inhibitors are the substances which decrease the activity of enzyme. These inhibitors either attach directly with enzyme or it's activator, then the activity of enzyme is stopped. The inhibitors are of two types. a. Competitive inhibitors b. Non-competitive inhibitors 5. WATER: Water also plays an important role to affect the activity of enzymes. In germinating seeds, water enter the body and helps to produce enzymes. The enzymes become active during germination.


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6. RADIATION: Ultraviolet rays; B-rays, y-rays and x-rays destroy the activity of enzymes.


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Chapter 4 THE CELL CELL: The cell is the smallest fundamental, structural and functional unit of living organisms or cell is the basic unit of life. The discovery and study of cells became possible after the invention of microscope. The microscope was invented by an Italian scientist Galilio in 1610. The word cell was first used by a scientist Robert Hooke in 1665. He observed a piece of cork under microscope and found many small chambers in it. He named each chamber as a cell. Another scientist Robert Brown discovered a rounded body in the cells of orchids in 1831. This body was named as nucleus. CELL THEORY: This theory was proposed by two German scientists. Schleiden (1838), Schwann (1839) and Virchow. It is a fundamental theory. The main points of this theory are as follows: i. All organisms are composed of one or more cells. ii. The cell is the structural and functional unit of life. iii. All the new cells are produced by the division of pre-existing cells. iv. The cells contain a hereditary material, the nucleic acid. It transfers the hereditary characters into the new cells. v. Each cell have life. It takes energy from it's environment. This energy used in the formation of important compound, protoplasm and other organisms. MICROSCOPE: Microscopes are the instruments which are used to observe microorganisms or small organisms. KIND OF MICROSCOPES: There are different kinds of microscopes. These kinds are as follows: 1. Light microscope 2. X-ray microscope 3. Electron microscope 1. LIGHT MICROSCOPE: In this microscope visible light is used as a source of illumination. In 13th century convex lenses were invented. These lenses are used in the microscope. There is a stage on which slide of specimen is placed to observe by the help of lens. This microscope is of two types. i. Simple microscope of dissecting microscope: ii. Compound microscope


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2. X-RAY MICROSCOPE: In this microscope short wave length X-rays are used as source of light. This microscope is very efficient instrument to observe the three dimensional structure of cell parts. By the help of this microscope X-ray beams are focused by electromagnetic electromagnetic lenses or reflecting curved mirrors, the image of object is formed on the film. 3. ELECTRON MICROSCOPE: In this microscope electron beam is used for illumination. This microscope is designed by German scientists knol and rusk in 1932. Other scientists also contributed in it's design, such as Marton of Belgium, prebus and Miller of Canada from 1932-1934. TECHNIQUE TO ISOLATE THE COMPONENTS OF THE CELL: i. To determine the chemical composition of various parts of a cell, its components are isolated, this process is known as fractionation. ii. In fractionation many similar types of cells are placed in cold environment in a homogenizer and then spinning action is applied, called centrifugation. iii. At low speed s peed larger particles like cell nuclei are s eparated and these are settled down in the bottom, in the sediments. iv. Smaller particles remain in the fluid, which are transferred into another test tube. These particles are centrifuged at high speed, it helps to separate these particles in various fractions. After their separation, they can be studied easily. CELL WALL: The cell wall is present in plant cell on the outer side of plasma membrane. It is composed of cellulose, but it also contains lignin and pectin which make it stronger. In a younger cell, the cell wall is thin and delicate, but in a large cell it becomes thick and strong. The cell wall consists of three layers. i. Primary wall ii. Secondary wall iii. Middle lamella i. PRIMARY WALL: It is found around a young plant cell on the outerside of plasma membrane. ii. SECONDARY WALL: It is formed on the inner side of primary wall in an o ld and large cell. After it's formation the cell wall becomes thick and non-elastic. iii. MIDDLE LAMELLA: It is the layer between the two cells. It helps to attach the cells. It is made up of calcium and magnesium pectates. FUNCTIONS OF CELL WALL:


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1. It gives a definite shape and structural frame work to the cell. 2. It protects the inner contents of the cell. 3. It provides mechanical support to the cell. 4. It is a permeable membrane for diffusion and helps in the absorption of minerals and solutes along with water in the cells of root hairs. STRUCTURE STRUCTURE AND FUNCTIONS OF NUCLEUS: The nucleus was discovered by a scientist Robert Brown in 1831. It is spherical or oval in shape and is located in the centre in a young cell while in a mature cell it comes to lie on one side. STRUCTURE OF NUCLEUS: i. NUCLEAR-MEMBRANE: NUCLEAR-MEMBRANE: The nucleus is surrounded by a thin, transparent membrane known as nuclearmembrane. It separates the cytoplasm from the nucleus. The nuclear membrane has numerous large pores which help in direct communication between cytoplasm and the nucleoplasm. ii. NUCLEOPLASM: NUCLEOPLASM: In the nucleus there is a dense but clear mass of protoplasm, called nuclear-sap or nucleoplasm. It contains enzymes and other complex substances which take part in the formation of DNA and RNA. iii. CHROMATIN NETWORK: In the neoplasm a network o f fine loosely connected threads is present, called chromatin network. The chromatin is the hereditary material. In division of nucleus the chromatin forms a definite number of thread like structures, called chromosomes which contain hereditary units on their surface, called genes. Chemically chromatin consists of ribonucleic-acid (RNA) and Deoxyribonucleic acid (DNA). iv. NUCLEOLUS: NUCLEOLUS: In each nucleus o ne or more globular bodies are present, called nucleolus. They consists of proteins and RNA. The nucleolus produces ribosomes, which take part in protein synthesis. FUNCTIONS OF NUCLEUS: 1. The nucleus controls all the vital activities of a cell, so it is considered as the brain of the cell. 2. It produces chromosomes during cell division. The chromosomes transfer hereditary characters from parent cell to daughter cell. 3. It directly takes part in cell division and reproduction.


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4. It produces DNA and RNA. DNA is a generic material and RNA takes part in protein synthesis. 5. In the nucleolus of nucleus ribosomes are produced, which help in protein synthesis. STRUCTURE AND FUNCTIONS OF ENDOPLASMIC RETICULUM: It is a network of fine tube like structures, which extend from cell membrane to the nuclear membrane. It is of two types. It consists of lipoproteins. i. Agranulated or smooth endoplasmic reticulum (SER) ii. Granulated or rough endoplasmic reticulum (RER) Smooth endoplasmic reticulum does not contain ribosomes on their surface. It is found in steroid producing cells, like fat cells, liver and muscles. In skin the smooth endoplasmic reticulum converts cholesterol into vitamin D (a lipid compound). This vitamin helps to make bones strong and healthy. Rough endoplasmic reticulum contain ribosomes on their outer surface. This reticulum is found in the cells which take part in protein synthesis, such as pancreas and salivary glands of mammals. FUNCTIONS: i. It helps in the exchange of important materials between cytoplasm and nucleus. ii. It is involved in protein synthesis due to the presence of ribosomes. iii. It is the passage for RNA to transfer from nucleus to the cytoplasm. iv. It takes part to neutralize the harmful effect of drugs. v. It helps in detoxification of chemicals. vi. In skin smooth endoplasmic reticulum converts cholesterol into a lipid compound, called Vitamin-D in the presence of sunlight. This vitamin makes the bones healthy and strong. MITOCHONDRIA OR CHONDRIOSOMES: They are small spherical or plate like bodies present in the cytoplasm. Mitochondria are transferred from mother to the new generation. These are present in eggs and not in sperms, so mother transfers them into new generation. Mitochondria consist of 3 parts. 1. AN OUTER MEMBRANE: It is smooth and consists of proteins and lipids. 2. INNER MEMBRANE: It forms numerous folds, called cristae. On these cristae enzymes and coenzymes are present which help in the oxidation of starch, fatty acids and amino


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acid. These compounds are converted into CO2 and water. In this process energy is released in the form of ATP. This energy is stored in the mitochondria. 3. MATRIX: It is the central granular part. It contains many organic compounds. FUNCTIONS: Mitochondria are the main centres of the intercellular energy production, they are called power-house of the cell. Almost all the respiratory activities take place in mitochondria and they contain a n umber of enzymes.

GOLGI APPARATUS OR DICTYOSOMES: The golgi bodies are found only in certain types of cells. In plant cells they are present throughout the cell, while in animal cell single golgi complex is present. Each golgi body consists of a. Flattened sac like structures, called c isternae, b. Outer network of connecting tubules and c. Certain vesicles or golgian vacuoles. FUNCTIONS OF GOLGI BODIES: i. Golgi bodies take part in the formation of protein and carbohydrates, called glycoproteins. ii. In animal cell they are associated with the secretion of certain enzymes, hormones and other substances. iii. In plant cell they are involved in the formation of cell wall and cell plate. LYSOSOMAL STORAGE DISEASES: When the function of lysos omes is disturbed, it causes many abnormal conditions or diseases. W.G. Hers of Belgium in 1965 explained that when a lysosomal enzyme, a-glycosidase is not produced in the body, it results in the storage o f undigested glycogen, it is accumulated in lysosome, due to which organelles become swollen and cells and tissues are damaged, such diseases in which there is deficiency of lysosomal enzyme and accumulation of undigested glycogen, are called lysosomal storage disorders. There are more than 30 disorders of lysosomal storage. Some of them are as follows: a. TAYSACHS DISEASE: It is a dangerous disease. It causes blindness and mental retardation. Due to this disease death of baby may occur by the age of three years. b. GAUCHER'S DISEASE:


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This disease causes mental retardation in infants. Due to this disease liver and spleen become enlarged and erosion of long bones takes place i.e. bones are damaged badly. c. KRABBE'S DISEASE: This disease causes loss of myelin, mental retardation. It may cause death of baby by the age of two years.


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Chapter 5 VARIETY OF LIFE CLASSIFICATION: There are different kinds of living organisms in the world. These organisms differ from each other in size, shape and colour they are classified into different groups and sub groups on the basis of their characters. This system of classification is known as taxonomy. The living organisms are classified on the bases of following characters: 1. Homology 2. Comparative biochemistry 3. Cytology 4. Genetics 1. HOMOLOGY: The living organisms of a particular groups have some similar characters, this characteristic is called Homology. The organs of the body which have same fundamental structure but different in their function are c alled homologous organs, for example legs of horses, flippers of turtles, wings of birds are homologous organs. They have the same fundamental plan, show different structure but perform common function i.e. locomotion of the body. The homologous organs in different animals show relationship and prove that they have evolved from a common ancestor. In this way homology is a v ery important character for classification of living organisms. 2. BIOCHEMISTRY (Chemical constituents): When morphological characters are not helping in the classification of living organisms, then their chemical constituents are used, for example in bacteria study of chemical structure is useful to identify and classify them, because they have similar cellular structure. In biochemistry certain techniques are used, such as chromatography and electrophoresis, so their chemical constituents can be studied properly. Amino acid sequence in the proteins or arrangement of nitrogen bases in DNA help to classify the organisms and to determine their evolutionary relationship. 3. CYTOLOGY: Cytology also helps in the classification of living organisms. By the help of electron microscope it is proved that in bacteria and cyonobacteria (blue green algae), incomplete nucleus is present, so they are placed in the same K ingdomMonera. Prokeryotic and eukaryotic organisms have been identified on the bases of microscopic study. Cell study has also helps to know about the number of chromosomes in different organisms. All plants and animals contain particular fixed number of chromosomes.


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4. GENETICS: It is the final technique, which is applied in taxonomy, because all characters are inherited from parents to new generation. All morphological. Biochemical and cytological characters are based upon genetic combination. DNA study is very useful in the classification of organis. UNITS OF CLASSIFICATION OR TAXONOMIC CATEGORIES: In classification of plants different units are used. In 18th century scientists presented the system of classification and formed it's units. The lowest and basic unit is called species. According to the classification system the similar individuals in a group that breed with one another are called species. They resemble with one another very closely. The different groups of plants are called Taxa. Each plant belongs to a species. Species with many similar characters are placed in a genus, many genera from family. Many families with certain similar characters are grouped in order. A group of similar orders belongs to a class. Many closely related classes constitute a division (or phyla) and many phyla are included in a kingdom. VIRUSES: Viruses are very minute non-cellular bodies, considered between living and non living. The word virus is derived from a Latin world vios, means poison. They are obligate parasites and reproduce only in the liv ing cells. They are visible under electron microscope. In 1892 a Russian virologist Ivanovasky indicated the existence of virus in tobacco mosaic disease. PROPERTIES OF VIRUSES: 1. Virus are non-cellular parasitic organisms, minute in size from 25nm to 250nm. 2. They are considered on the border of living and non living because they are alive in the body of living organisms and dead outside the living body. 3. Viruses are obligate parasites. They reproduce only i nside living cells. When they enter a host cell, they control the biochemical activities of the cell. 4. They are composed of nucleic acid and proteins. 5. Virus has no cell wall, cytoplasm and proper nucleus. STRUCTURE OF VIRUSES: Structurally there are different shapes of virus. They are rounded, rod-shaped, tadpole like or polyhedral. i.e. consist of many sides. Many viruses have helical or isometric structure. Helical viruses are rod-shaped or thread like with numerous helix like (screw like) subunits. e.g. Tobacco mosaic virus (TMV). Isometric viruses are spherical in shape. Virus consists of different parts: i. Viral genome ii. Capsid


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iii. Envelopes or covering iv. Tail fibres i. VIRAL GENOME: It is the inner part, the nucleic acid. It consists of a single or many molecules of DNA or RNA. In small virus four genes and in the largest virus several hundred molecules are present. In many viruses nucleic acid is different. In animal viruses and bacteriophage usually DNA is present and in plant viruses mostly RNA is present. In viruses cytoplasm, nucleus and chromosomes are not found. ii. CAPSID: The central part genome or nucleic acid of virus is covered by an outer protein coat, called Capsid. The Capsid is made up of numerous protein units, called capsomeres. The Capsid with nucleic acid is called nucleo-capsid. In simplest viruses Capsid is made up of one or a few different protein molecules. In complex viruses many different kinds of proteins are present in Capsid. iii. VIRAL ENVELOPES: These are membranous covering around the Capsid. It is found in some viruses. This covering helps them to infect their hosts. iv. TAIL FIBRES: In bacteriophage virus lower part is tail like. At the posterior end of tail some fibre like structures are present, called tail fibres. These fibres take part in the attachment of virus with host cell. LYTIC CYCLE OF BACTERIOPHAGE: The reproductive cycle of virus which causes death of the bacterial cell is called lytic cycle. Due to the infection bacterial cell ruptures and bacteriophage viruses are released. Each phage can infect another cell. Bacteriophage often consist of a head and a hollow tail region. From the tail fibrils are produced. Around the tail a protein sheath is also present. The steps of lytic cycle are as follows: 1. The virus first attaches to the bacterial cell by its protein tail. An enzyme lysozyme is secreted by the tail which helps to dissolve the bacterial cell wall. 2. The D.N.A. of virus is transferred into the bacterial cell from the head region and the protein coat of the head and tail remains outside. 3. Inside the bacterial cell the viral D.N.A. then controls the bacterial cell activity. The duplication of viral D.N.A. takes place and the new phage particles start to produce inside the cell.


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4. It also allows the bacterial cell to produce only the viral type of protein. In this way D.N.A. and protein of virus are developed in bacterial cell. 5. The D.N.A. of the virus is migrated into the head portion. 6. After a particular period the bacterial cell bursts and new bacteriophages (viruses) are set free. This process is called lysis. This type of cycle is known as lytic cycle. LYSOGENIC CYCLE OF BACTERIOPHAGE: Some times the viral D.N.A. in bacterial cell does not take the control of biochemical activity. The D.N.A. of virus and bacteria make an association. In this way many new generations of bacteria can be produced without any harmful results. Virus that has both type of reproduction in bacterial cell is called temperate virus. When D.N.A. of virus enters the bacterial cell, it forms a circle and forms an association with bacterial chromosome. Virus in this state is called prophage. It remains inactive without any harm in bacterial cell. When bacteria reproduces, each time viral DNA also replicates and transfers into new cell. The bacteria which are not affected by the viral DNA are called lysogenic bacteria and the cycle is known as lysogenic cycle. Sometimes due to certain reasons such as radiation or chemicals the viral DNA becomes active again and then it starts lytic cycle again. Then it destroys the bacterium as in the lytic cycle.


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Chapter 6 KINGDOM PROKARYOTA (MONERA) STRUCTURE OF BACTERIA: Bacteria are simplest and smallest living organisms. The s ize of bacterial cell is 0.2 micron to 2 in breadth and 2 to 10 micron in length. Bacteria are unicellular but may form groups or colonies. A bacterial cell consists of following parts: 1. Flagella 2. Pilli 3. Capsule 4. Cell wall 5. Cell membrane 6. Cytoplasm 7. Mesosomes 8. Nuclear material 1. FLAGELLA: Flagella are thin hair like s tructures arise from basal body, a structure present beneath the cell membrane. Flagella are locomotory organs of bacteria i.e. help in the movement of the body. 2. PILLI: These are fine, hollow, filament like structures. These are not used in locomotion, but help in conjugation process of reproduction. 3. CAPSULE: It is an additional protective layer around the cell wall and found in some bacteria. It is composed of polysaccherides and proteins. In some bacteria slim-capsule is present, which is used for the protection of bacterial cell against phagocytosis and increases the activity of bacterial cell. 4. CELL WALL: It is present around the bacterial cell. It is composed of amino acids, sugars and chitin. Cellulose is not present in bacterial cell. In some bacteria capsule is also present around the cell wall. 5. CELL MEMBRANE:


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Internal to the cell wall, cell membrane or plasma membrane is present. The protoplasm of bacterial cell is bounded by cell membrane. It is composed of lipids and proteins. 6. CYTOPLASM: The cytoplasm is a fluid material. It is dense and contains granules of glycogen, proteins and fat. Mitochondria and endoplasmic reticulum are absent. In the cytoplasm ribosomes are present. They are small minute granules co mposed of protein and R.N.A. and help in protein formation. 7. MESOSOMES: The plasma membrane of bacterial cell is folded inward to form a special structure, called mesosomes. The mesosomes take part in cell division, DNAreplication, secretion of certain enzymes, respiration and active transport of enzymes. 8. NUCLEAR MATERIAL: There is a distinct nuclear region in the bacterial cell, but without nuclear membrane and nucleolus. The nuclear region contains the genetic material D.N.A. bacteria are haploid organisms with a single c hromosome. The chromosome consists of a circular double helical DNA molecule. The single molecule of DNA contains several thousand genes. The genetic material replicate at the time of cell division and it is transferred to the daughter cell.

GRAM POSITIVE AND NEGATIVE BACTERIA: Certain bacteria are stained with a violet: dye during colouring procedure. They are called Gram positive bacteria. It was discov ered by a Danish microbiologist Hans Christian Gram. Other bacteria do not stain with the violet dye, they are known as Gram negative bacteria. This property of bacteria helps in the identification of unknown bacteria and also in the grouping of different kinds of bacteria.

RESPIRATION IN BACTERIA: According to the respiration there are two types of bacteria. i. AEROBES: These bacteria need oxygen for respiration. Aerobes bacteria are of two types: a. OBLIGATE AEROBES: These bacteria require O2 and die in its absence. b. FACULTATIVE AEROBES: These bacteria used O2, but can also survive in it's absence. The bacteria which require little amount of O2 are called microaerophilic bacteria.


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ii. ANAEROBES: These bacteria do not need O2 for respiration. Anaerobes bacteria are of different types: a. OBLIGATE ANAEROBES: Some bacteria are killed in the presence of O2. These are called obligate anaerobes. b. FACULTATIVE ANAEROBES: The bacteria which use O2 but also can respire without it, they are called facultative anaerobes.

GROWTH IN BACTERIA: Growth is an increase in the number of cells and size of cells. Bacteria take their food from the environment by diffusion or active transport process. Oxygen is required for aerobe bacteria and it is not needed for anaerobe bacteria. The factors which affect the growth are: i. Temperature ii. Available nutrients iii. pH iv. Ionic concentration STAGES OR PHASES OF GROWTH: In bacteria there are four phases of growth: 1. Lag phase 2. Log phase 3. Stationary phase 4. Death phase or decline phase 1. LAG PHASE: This is inactive phase of bacteria. In this stage bacteria prepare themselves for growth. The cells accumulate essential substances such as water and proteins. 2. LOG PHASE: The logarithmic phase (log phase) is the period in which bacteria grow very rapidly. Their metabolic activities are maximum. Their rate of reproduction is more and rate of death is very slow. So they increase their number rapidly. 3. STATIONARY PHASE:


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After an active growth the bacteria face shortage of food, pH changes and energy is less, so they try to maintain themselves. They also start dying as a result of which their multiplication is equal to their death rate. The number of cells is almost unchanged, so it is called stationary phase.

4. DEATH PHASE: When conditions are totally unfavorable, death occurs rapidly than growing cells. When death rate is faster than multiplication rate, it is called death phase.

IMPORTANCE OF BACTERIA: Bacteria have both positive and negative importance. They play very important role in the life of human being. POSITIVE IMPORTANCE: 1. DECAYING OF DEAD BODIES: (DECOMPOSERS) Bacteria decompose the dead remains of plants, animals and human beings into simpler compounds. in this way they help to clean the world. 2. BACTERIA IN INDUSTRIES: i. Bacteria are used in dairy industry. They change the milk into curd. ii. They are used in the formation of butter and cheese from milk. iii. They are used in the ripening of tobacco leaves. iv. Bacteria are used in the preparation of alcohol and vinegar. v. Bacteria are also used in leather industry. 3. DIGESTION IN ALIMENTARY CANAL: Certain Bacteria are present in the intestine of man and help in the digestion of cellulose, by enzyme, called cellulase. 4. FERTILITY OF SOIL: Bacteria increase the fertility of soil by adding organic substances due to the decomposition of dead bodies. 5. GENETIC ENGINEERING: (BIO-TECHNOLOGY) Bacteria are used in genetic engineering. Escherichia coli bacteria are used to produce growth hormones, and production of insulin. NEGATIVE IMPORTANCE: 1. SPOILAGE OF FOOD: Bacteria spoil our food stuff in large amount by the chemical process. It is a great loss.


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2. DISEASES IN MAN: Bacteria are responsible to cause various diseases in man and other animals, such as tuberculosis (T.B.), pneumonia, cholera, typhoid, tetanus, syphilis, Diphtheria etc. 3. DISEASES IN PLANTS: Bacteria also cause diseases in various plants, such as citrus canker. Five blight of apple, ring disease of potato, wilt of solanaceae plants etc.

CONTROL OF BACTERIA: The different methods to control the infectious microorganisms are as follows: 1. Infected persons should be properly treated by effective medicines. 2. Persons in a population should be treated by immunization and vaccination. 3. In epidermic condition the infected persons should be kept in quarantine to avoid the spread of infection to healthy persons. 4. At different possible stages the life cycle of pathogen should be disrupted, so it can not cause further infection. 5. The host bodies of pathogen should be identified and treated well to control the disease. 6. By different ways knowledge and awareness about diseases and infection of pathogen should be provided to the public. Many methods should be used to kill or inhibit the infection of pathogens, such as: a. High temperature treatment b. By ultraviolet rays c. By the use of antiseptics d. By the use of antibiotics e. By chemotherapy

USE AND MISUSE OF ANTIBIOTICS: Antibiotics are the chemical substances which are used to kill micro-organisms that cause infectious diseases. These are produced by certain micro-organisms and prevent the activity of other micro-organisms. USE OF ANTIBIOTICS: 1. Antibiotics have their effect against the bacteria and kill them and control their infection. 2. The antibiotics are used as vaccination to develop resistance in the body. They maintain immune system.


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3. Antibiotics are also used in agriculture to kill different organisms. These are also used in animal feeds to provide growth promoting substances. MISUSE OF ANTIBIOTICS: 1. By the extensive use of antibiotics more resistance is developed in pathogenic micro-organisms, after that they cause more serious infection in the body. 2. Antibiotics have many side-effects. Other organs of the body may be damaged, such as liver cells and kidney cells. 3. Antibiotics may react with human metabolism and in severe cases death of person may occur. 4. Some antibiotics cause allergy in the body, such as penicillin.

CYNOBACTERIA (BLUE-GREEN ALGAE): i. They are water living simple organisms. ii. They are prokaryotes i.e. they do not have true nucleus. Like bacteria, so called cyanobacteria. iii. They contain blue green pigments, chlorophyll a (green) and phycocyanin ( blue), so they are also called blue green algae. iv. They are unicellular or may be found in groups or colonies. v. They have double-layered cell wall. vi. Asexual reproduction takes place by hormogonia, fragmentation, akinetes or zoospores. vii. Sexual reproduction is absent.

IMPORTANCE OF CYANOBACTERIA: 1. These organisms take part in nitrogen fixation. Nostoc and anabaena are used as nitrogen fertilizer in agriculture to improve the soil fertility. 2. During photosynthesis they use CO2 and H2O. They release oxygen as a by product. In this way they take part to change and flourish the environment. 3. Many organisms of cyanobacteria are found in the form of phytoplankton. They are used as food by many aquatic animals. 4. They also produce unpleasant smell in water and make it unable for drinking.


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CHAPTER 7 KINGDOM PROTOCTISTA

STRUCTURE AND REPRODUCTION OF CHLORELLA: Chlorella is green alga. It grows in fresh water places, such as ponds, ditches and pools etc. Chlorella is unicellular or found in groups. The cells are small and spherical. Each cell is covered by a thin cell wall, composed of cellulose. In the cell cytoplasm is present. In the centre of cell nucleus is present. Each cell also contains a cupshaped chloroplast. In the chloroplast pyrenoid is sometimes present or sometimes absent. Pyrenoid is a starch-forming body. In c hlorella flagella are absent i.e. it is non-motile. REPRODUCTION: Chlorella has only asexual reproduction. It takes place by aplanospores. At the time of reproduction the cytoplasm of cell divides into 8 or 16 small bodies. Each body is covered by a wall, it is called aplanospore. In this way 8 or 16 aplanospores are formed in a cell. After maturation of aplanospores the cell wall ruptures and all aplanospores become free. Each aplanospore can develop into a new cell. ECONOMIC IMPORTANCE OF CHLORELLA: 1. Chlorella cells have very high food value. They contain about 50% proteins, 20% carbohydrates and 20% fats, amino acids and vitamins, so it can be an alternate source of food. 2. From chlorella an important antibiotic chlorellin has been isolated. It is useful to control bacterial diseases. 3. Chlorella is used in important physiological experiments. Because it is easily cultivated. It is used in the research on photosynthesis and respiration.

STRUCTURE OF ULVA: Ulva belongs to the green algae. It grows in marine water and is considered as a primitive plant in the group. It is also known as sea-letuce. It's body is called thallus which consists of erect broad sheet-like branches, or blades. From the base of plant thread like colourless structures are given out which help in the attachment of plant to any rock or stone and thus act like a hold-fast. The hold fast does not absorb water. The body of Ulva is composed of two layers of cells. The outer layer has contact with water, while the inner layer is prevented from the water contact. The cells are elongated. Each cell contains cytoplasm, a nucleus and a single cup-shaped chloroplast.


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LIFE-CYCLE OF ULVA: The life cycle of Ulva is completed in two stages. The first stage is gametophyte, in which the male and female gametes are produced by separate plants. These gametes unite together to form zygote. The zygote develops into sporophyte, which is the second stage of life cycle. The sporophyte forms spores which produce gametophyte again. This whole process of life cycle is called alternation of generations. In Ulva gametophyte and sporophyte plants are similar in structure, so this process is termed as isomorphic alternation of generations. The life cycle is described as follows: 1. GAMETOPHYTIC STAGE: In this stage sexual reproduction takes place and two types of male and female gametes are formed. The male and female plants are separate but similar in structure. The male plant produces male gametes and female plant produces female gametes. These male and female gametes are externally similar and internally different, they are called isogametes. They come in water and fuse together to form zygote. The zygote is diploid and it contains 26 chromosomes. It germinates into sporophyte which is also diploid in nature. 2. SPOROPHYTIC STAGE: It is the second stage of the life cycle of Ulva. I t is developed by the germination of zygote. The sporophyte resembles to gametophyte in structure. The sporophyte produces zoospores by asexual reproduction. In the formation of zoospores meiosis takes place due to which they become haploid and contains 13 chromosomes. The zoospores become free after maturation. Half of the zoospores form male and half produce female gametophyte of Ulva plant. In this way it's life cycle is completed. SLIME MOLD: Slime mold are creeping multinucleate masses of cytoplasm, look like egg white. STRUCTURE OF SLIME MOLD: The body of slime mold consists of irregularly shaped mass of protoplasm, which is naked i.e. has no proper body wall. The naked protoplasm is bounded by a non-cellular, thin flexible slimy layer. Due to the presence of slime layer it is called slime mold. Within the s lime layer protoplasm also contains plasma membrane. Slime mold has no proper shape and size. The protoplasm consists of outer ectoplasm and inner endoplasm. The protoplasm contains many diploid nuclei. This body of slime mold is called plasmodium. It produces pseudopodia and shows amoeboid movement, so it seems to be like a gaint amoeba. By the help of pseudopodia it engulfs and digest bacteria and food particles, so it also contains food vacuoles and undigested food particles in the cytoplasm.

ZOOLOGY PART:

CLASSES OF PHYLUM PROTOZOA: The phylum protozoa is divided into following classes: 1. Class - Mastigophora - Flagellata


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2. Class - Rhizopoda or Sarcodina 3. Class - Ciliata 4. Class - Suctoria 5. Class - Sporozoa

CLASS - RHIZOPODA OR SARCODINA: 1. They have very soft body wall, which can change the shape of the body. In some animals the body is covered by a shell. E.g. Globigerina. 2. From their outer surface pseudopodia are produced which help in locomotion and to capture the food. 3. The protoplasm is divided into ectoplasm and endoplasm. 4. Nucleus is one or more. 5. Excretion takes place by contractile-vacuole. In marine animals contractile vacuole is absent.

CLASS - SUCTORIA: These animals have close relationship with Ciliata animals and they seem to be evolved from them. Their characters are as follows: 1. They have cilia which help in s wimming but the adult animals are without cilia. They are attached to any solid object by the help of a long rod-like structure. 2. They contain two types of nuclei, micronucleus (smaller) and meganucleus (large). 3. From their body certain thin structures are developed, called tentacles. Some tentacles are pointed and penetrate into the body of prey. Some tentacles have knob-like bodies at their tips which help to capture the prey. Tentacles secrete a poisonous substance to paralyse the prey. 4. Reproduction takes place by budding e.g Acinata.

CLASS - CILIATA: 1. Their body is provided by cilia, which help in locomotion and to get food into the body. 2. They have mouth, through which the food enters the body. The food may also be taken through the general surface. 3. They contain two nuclei, micronucleus and meganucleus.


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4. Body is covered by pellicle. 5. Excretion takes place by contractile vacuole.

CLASS - SPOROZOA: 1. The animals of this class are usually parasites. 2. They do not produce special organs for locomotion. They perform very slow movement, called amoeboid movement. 3. They contain cytoplasm and nucleus. 4. Reproduction takes place by asexual sexual methods. 5. They cause some dangerous diseases in man and other vertebrates such as malaria by plasmodium. 6. Their life cycle is completed in the body of two hosts. One is the body of vertebrate and other is the body of invertebrate. The plasmodium is transferred into the body of man from the body of female anopheles mosquito.


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CHAPTER 8 KINGDOM - FUNGI STRUCTURE OF THE BODY OF FUNGUS: MYCELIUM: The complete multicellular body of fungus is called MYCELIUM, which is composed of white fluffy mass of branched hyphae. HYPHAE: A few of true fungi are unicellular (such as yeast) but most have multicellular body (mycelium) consisting of long, slender, branched, tubular, thread like filaments called as Hyphae which spread extensively over the surface of substrate. TYPES OF HYPHAE: Hyphae can be divided in to two types: 1. Septate or Multicellular Hyphae 2. Non-septate or multinuclear or coenocytic hyphae.

1. SEPTATE HYPHAE: “Those hyphae which are separated by cross-walls called “septa” into individual cells containing one or more nuclei , are called “Septate Hyphae” EXAMPLE: Mushrooms 2. NON-SEPTATE HYPHAE: Those hyphae, which lack septa & are not divided into individual cells, instead these are in the form of long, multinucleated large cells are called Non-septate or Coenocytic Hyphae. EXAMPLE: Mucor & Rhizopus CELL WALL OF HYPHAE: CHITIN is the chief component present in the cell wall of most fungi, Because it is more resistant to decay than are the Cellulose & lignin which make up plant cell wall. CYTOPLASM OF HYPHAE: In septate Hyphae ----- Cytoplasm flows through the pores of septa from cell to cell, carrying the materials to growing tips & enabling the hyphae to grow rapidly,


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under favorable conditions. In non-septate hyphae ------ cytoplasm moves effectively, distributing the materials throughout.

NUCLEI OF HYPHAE: All fungal nuclei are HAPLOID except for transient diploid zygote that forms during sexual reproduction. MAIN FUNCTION OF HYPHAE: Extensive spreading system of Hyphae provides enormous surface area for absorption.

NUTRITION IN FUNGI: ABSORPTIVE HETEROTROPHS: All fungi lack chlorophyll & are heterotrophs ( obtain carbon & energy from organic matter, They obtain their food by direct absorption from immediate environment & are thus “ABSORPTIVE HETEROTROPHS”. DIFFERENT MODES OF HETEROTROPHIC NUTRITION IN FUNGI: Being Heterotrophic, fungi can exist as 1. Saprotrophs or saprobes (Decomposers) 2. Parasites 3. Predators 4. Mutualists

1. SAPROBIC OR SAPROTROPHIC FUNGI ( DECOMPOSERS): Saprobic fungi along with bacteria, are the major decomposers of biosphere, contributing to the recycling of the elements (C,N,P,O,H & etc) used by living things. “Those fungi which obtain their food (energy, carbon & nitrogen), directly by digesting the dead organic matter are called “SAPROBIC FUNGI” OR “DECOMPOSERS”

2. PARASITIC FUNGI: Those fungi which absorb nutrients directly from liv ing host cytoplasm are called PARASITIC FUNGI.

TYPES OR PARASITIC FUNGI: Parasitic fungi may be of two types


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a. Obligate parasites b. Facultative parasites

a. OBLIGATE PARASITES: Those parasitic fungi which can grow only in their living host & cannot be grown on available defined growth culture medium, are called “ Obligate Parasites”. EXAMPLES: Many mildews Most of Rust species. b. FACULTATIVE PARASITES: “Those parasitic fungi which can grow parasitically on their host as well as by themselves on artificial growth media, are called “ Facultative Parasites”. 3. PREDATORY FUNGI: “Those fungi which obtain their food by killing other living organisms are called PREDATORY FUNGUS. EXAMPLES: a. Oyster Mushrooms (Pleurotus astreatus). b. Some species of Arthrobotrys.

a. IN OYSTER MUSHROOMS: Oyster mushroom is a carnivorous fungus. It Paralyses the nematodes (that feed on this fungus), penetrate them & absorb their nutritional contents, primarily to fulfill nitrogen requirements. It fulfill it glucose requirements by breaking the woods. b. IN ARTHROBOTRYS: Constrictor ring development Some species of Arthrobotrys trap soil nemotodes by forming CONSTRICTING RING, their hyphae invading & digesting the unlucky victim. 4. MUTUALISTIC FUNGI: “Those fungi which form such symbiotic associations with other living organisms in which both partners of association get benefit from each other are called MUTUALISTIC FUNGI & Such association are called as “MUTUALISTIC SYMBIOTIC ASSOCIATIONS”

TWO MUTUALISTIC SYMBIOTIC ASSOCIATIONS FORMED BY FUNGI: Fungi form two key mutualistic symbiotic associations. These are:


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1. LICHENS 2. MYCORRHIZAE

1. LICHENS: SYMBIOTIC PARTNERS IN LICHENS: Lichens are mutualistc & have symbiotic associations b/w certain fungi (mostly Ascomycetes) & imperfect fungi & few Basidiomycetes (about 20 out of 15000 species of lichens) & certain photoautotroph either green algae or c ynobacterium or sometimes both. MUTUAL BENEFIT: In lichens, fungi protect the algal partner from strong light & desiccation & itself gets food through the courtesy of alga. AREAS WHERE LICHENS GROW: Lichens can grow at such places such as bare rocks & etc, where neither of the components alone can grow. ECOLOGICAL IMPORTANCE OF LICHENS: From ecological point of view, lichens are very important because they serve as BIO INDICATORS of AIR POLLUTION. 2. MYCORRHIZAE: SYMBIOTIC PARTNERS: Mycorrhizae are mutualistic association b/w certain fungi & roots of vascular plants (about 95% of all kinds of vascular plants). MUTUAL BENEFIT: The fungal hyphae dramatically increase the amount of soil contact & total surface area for absorption & help in direct absorption of nutrients from soil. The plant on the other hand, s upplies organic carbon to fungal hyphae. TYPES OF MYCORRHIZAE: There are two main types of mycorrhizae. 1. Endomycorrhizae 2. Ectomycorrhizae 1. ENDOMYCORRHIZAE: In Endomycorrhizae, the fungal hyphae penetrate the outer cells of plant root, forming coils, swellings & minute branches, & also extend out into surrounding soil.


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2.ECTOMYCORRHIZAE: In Ectomycorshizae the hyphae surround & extend between the cell but don’t penetrate the cell walls of roots. EXAMPLE: Mutualistic association between fungi & pines & firs.

CLASSIFICATION OF FUNGI: There are four major divisions of fungi, which are divided on the basis of their sexual reproduction. 1. ZYGOMYCOTA 2. ASCOMYCOTA 3. BASIDIOMYCOTA 4. DEUTEROMYCOTA

1. ZYGOMYCOTA: INTRODUCTION: Zygomycota are by far the smallest of four groups of fungi, with only about 600 named species. This group includes more frequently bread molds as well as a variety of other microscopic fungi found on decaying organic material. CHARACTERISTIC FEATURE: The group is named after a characteristic feature of the life cycle of its member, the production of temporalily dormant structures called ZYGOSPORES. The zygomycetes lack septa in their hyphae i.e coenocytic hyphae, except when they form sporangia or gametangia.

2. ASCOMYCOTA: INTRODUCTION: The second division of fungi, the ASCOMYCOTA is a very large group of about 30,000 named species with many more being discovered each year. CHARACTERISTIC FEATURE: The ascomycota are named for their c haracteristic reproductive structure, the microscopic, club shaped ASCUS. TYPE OF HYPHAE: The hyphae of ascomycetes are divided by septa i. e septate hyphae, but the septa are perforated & the cytoplasm flows along the length of each hyphae. The


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septa that cut off the asci & conidia are initially perforated like all other septa, but later they often become blocked. LIFE CYCLE OF ASCOMYCOTA: In life cycle of ascomycota, Both sexual & asexual reproduction occurs. a. SEXUAL REPRODUCTION IN ASCOMYCOTA: Sexual reproduction occurs through following steps. 1. FORMATION OF MALE GAMETANGIUM OR ANTHERIDIUM: The hyphae of ascomycetes may be either homokaryotic & heterokaryotic. The cells of these hyphae usually contain from several to many nuclei. These cells form Antheridium or male gametangium. 2. FEMALE GAMETANGIUM OR ASCOGONIUM: The gametangium which develop beak like out growth called as TRICHOGYNE, is called female gametangium or Ascogonium. 3. FUSION OF MALE & FEMALE GAMETANGIUM: When antheridium is formed , it fuses with trichogyne of an adjacent ascogonium. Fusion of cytoplasm or plasmogamy occurs. 4. PAIRING OF NUCLEI: After plasmogamy, nuclei from antheridium then migrate through the trichogyne into the ascogonium, & pair with nuclei of opposite mating types. 5. FORMATION OF DIKARYOTIC HYPHAE & DIKARYOTICY: Dikarytic hyphae then arise from the area of fusion. Throughout such hyphae, nuclei that represent the two different original mating types occur ( DIKARYOTICY ) Such hyphae are also called as HETEROKARYOTIC HYPHAE. 6. FORMATION OF ASCOCARPS OR FRUITING BODIES: Excessive growth of monokaryotic or dikaryotic hyphae results in formation of massive structures of tightly interwoven hyphae, called as FRUITING BODIES OF ASCOCARPS, which corresponds to the visible portions of a morel or cup fungus. 7. ASCI FORMATION: Asci are special reproductive structures which are formed on special fertile layers of dikaryotic hyphae with in the Ascocarps. 8. SEPARATION OF ASCI: The ASCI are cut off by the formation of septa at the tips of heterokaryotic hyphens. 9. SYNGAMY:


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There are two haploid nuclei with in each ascus one of each of which belongs to different mating type. Fusion of these two nuclei occurs within each ascus called as SYNGAMY. 10. ZYGOT FORMATION: Syngamy results in zygote formation, which divides immediately by meiosis, forming four haploid daughter cells. 11. FORMATION OF ASCOSPORES: Four haploid daughter nuclei, usually divide again by mitosis , producing 8 haploid nuclei that become walled & called ASCOSPORES. 12. BURSTING OF ASCUS: In most Ascomycetes, the ascus becomes highly turgid at maturity and ultimately bursts, often at a perforated area, which may be pore or slit or lid 13. DESPERSION & GERMINATION OF ASCOSPORES: After bursting, the ascospores may be thrown as far as 30 cm. Under favorable circumstances they germinate giving new hyphae.

b. ASEXUAL REPRODUCTION IN ASCOMYCOTA (BY CONDIA FORMATION): The type of asexual reproduction in fungi in which large number of asexual spores called “CONIDIA are formed, each on germination giving rise to new mycelium is known as CONIDIAL REPRODUCTION. EXPLANATION: CONIDIA: Conidia are non-motile, asexual spores which may be produced in very large number & can survive for weeks, causing rapid colonization on new food. CONIDIOPHORES: Conidia are not developed inside the sporangium but they are usually cut off at the end of modified hyphae called CONIDIOPHORES, commonly in chains or clusters. EXAMPLE: Asexual reproduction by conidia formation is very common in ASCOMYCETES.

TYPES OF ASCOCARPS IN ASCOMYCETES: According to their shape, Ascocarps are of following three types: a. OPOTHECIUM: The ascocarps of cup fungi & the morels are open, with the asci lining the open cups called OPOTHECIUM.


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b. CLEISTOTHECIUM: Some ascocarps are closed & called as ‘CLESTOTHECIUM’ c. PERITHECIUM: Some ascocarps have small opening at the apex called as PERITHECIUM. Ascocarps of NEUROSPORA are of this type.

3. BASIDIOMYCOTA: INTRODUCTION: The basidiomycetes, third division of fungi have about 16,000 named species. More is known about some members of this group than about any other fungi. CHARACTERISTIC FEATURE: Basidiomycetes are named for their characteristic sexual reproductive structures, the BASIDIUM, which is club shaped like as ascus. LIFE CYCLE OF BASIDIOMYCOTA: In life cycle of Basidiomycota, reproduction is usually sexual. Asexual reproduction is not very important. a. SEXUAL REPRODUCTION IN BASIDIOMYCOTA: The life cycle of basidiomycetes begin with the production of hyphae which may be of two types. 1. Homokaryotic hyphae giving rise to primary mycelium. 2. Heterokaryotic hyphae giving rise to secondary mycelium. PRIMARY OR MONOKARYOTIC MYCELIUM: Homokaryotic or monokaryotic hyphae lack septa at first. Eventually, However, septa are formed between nuclei of these hyphae. A basidiomycete mycelium made up of monokaryotic hyphae is called PRIMARY MYCELIUM. SECONDARY OR DIKARYOTIC MYCELIUM: Mycelium of basidiomycetes, with two nuclei, representing the two different mating types b/w each pair of s epta, is called SECONDARY OR DIKARYOTIC MYCELIUM. Most of the mycelium of basidiomycetes that occur in nature is dikaryotic & often only dikaryotic mycelium is able to form basidiocarps. FORMATION OF BASIDIOCARP OR FRUITING BODY: Dikaryotic mycelium is responsible for the formation of FRUITING BODY in Basidiomycetes called as BASIDIOCARP, made up of tightly interwoven dikaryotic hyphae. FORMATION OF BASIDIUM:


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Basidium is characteristic reproductive structure of Basidiomycetes, which is club shaped & formed with in the Basidiocarp. This produces slender projection at the end called as STERIGMATA, in this way. SYNGAMY & ZYGOT FORMATION: Nuclear fusion or syangamy occurs in Basidium, giving rise to diploid zygote, the only diploid cell of the life cycle. MEIOSIS & BASIDIOSPORE FORMATION: Meiosis occurs immediately after the formation of zygot, resulting in the formation of four haploid nuclei, which are incorporated in Basidiospores. In most member of this division basidiospores are borne at the sterignata DISPERSION AND GERMINATION: Same as in Ascomycetes b. ASEXUAL REPRODUCTION IN BASIDIOMYCOTA: In contrast to their effective sexual reproduction, asexual reproduction is rare in most basidiomycetes. EXAMPLES OF BASIDIOMYCETES: MUSHROOMS TOAD STOOLS PUFF BALLS JELLY FUNGI SHELF FUNGI PLANT PATHOGENS CALLED RUSTS & SMUTS,

4.DEUTEROMYCOTA (FUNGI IMPERFECTI): INTRODUCTION: “The fungi that are classified is this group, are simply those in which the sexual reproductive stages have not been observed. In other words, most of the Fungi Imperfecti are as ascomycota that have lost the ability to reproduce sexually. There are some 17000 described species of this group.” CHARACTERISTIC FEATURE: Sexual reproduction is absent among Fungi Imperfecti LIFE CYCLE OF DEUTEROMYCOTA: Although in life cycle of deuteromycetes or Fungi Imperfecti, true sexual reproduction is absent, but there is certain type of GENETIC RECOMBINATION


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which seems to be responsible for some of the production of new pathogenic strains of wheat rust. GENETIC RECOMBINATION IN FUNGI IMPERFECTI PARASEXUALITY: In parasexuality, exchange of portions of chromosomes between the genetically distinct nuclei with in a common hyphae takes place. This is the special type of genetic recombination occurs in fungi Imperfecti. EXAMPLES OF FUNGI IMPERFECTI: Among the economically important genera of Fungi Imperfecti are 1. PENICILLIUM 2. ASPERGILLUS 3. Most of the fungi that cause skin diseases in humans, including athlete’s foot & ring worm are also fungi imperfecti.

ECONOMIC IMPORTANCE OF FUNGI: Fungi play a vast role in economic field they show both harmful & useful activities to human beings. USEFUL FUNGI: Following are some of the beneficial effects of fungi. FOOD: Many kinds of edible fungi are in the form of mushrooms, are a source of nourishing & delicious food dishes. But not all the mushrooms are edible. Some of them are poisonous & called as toad stools or death stool. Yeast, another kind of fungi, are utilized in baking industry. MEDICINES: Nearly two dozens antibiotics have been isolated from different types of fungi & bacteria, like Penicilliun from penecillium notatum Neomycin Chloromycetin Tetramycin & etc. FOOD PRODUCTION: Many kinds of Yeast are used in the production of bakery & brewery products. Some species of genus PENICILLIUM give characteristic flavors & aromas to the cheese. FERMENTATION:


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Species of Aspergillus, are used for fermenting soya sauce & soya paste. Citric Acid is produced commercially with members of this genus under highly acidic condition. SOIL FERTILITY: Fungi maintain the soil fertility by decomposing the dead organic matter e.g Mycorhizal fungi. PRODUCTION OF ORGANIC COMPOUNDS: May species of fungi are used in the production of organic compound such as vitamins, proteins & fats. Saccharomyces, synthesizes a range of vitamin B group. HARMFUL FUNGI: Following are some of the harmful effects of fungi, FOOD SPOILAGE: Saprophytic fungi cause tremendous amounts of spoilage of food stuff. 15-20% of worlds fruit is lost each year due to fungal attack. SPOILAGE OF WOOD & LEATHER ARTICLES: Many fungi spoil leather goods, woods, wool, books, timber, cotton & etc. WOODROTTING FUNGI destroy not only living trees but also structural timber. BRACKET/SHELF FUNGI cause lot of damage to store cut lumber as well as stands of timber of living trees. TOXINS: Many fungi are poisonous . AMANITA VERNA is a mushroom, which produces deadly poisonous substance known as AMANITIN, which causes serious problems in respiratory system & blood circulatory s ystem. FOOD POISONING: Some fungi during decomposing food release certain poisonous substances collectively known as MYCOTOXINS. Mycotoxins are the major source of food poisoning. DISEASES: Fungi cause a number of diseases in plants as well as in human beings. PLANT DISEASES CAUSED BY FUNGI: Fungi destroy many agricultural crops, fruits, ornamentals & other kinds of plants because they produce several enzymes that can breakdown cellulose, Lignin and even cutin. Following are some of the serious plant disease caused by Fungi. RUST & SMUT DISEASES: Rust & smut diseases are serious diseases of WHEAT, RICE, CORN &other cerial crops. They cause extensive damage.


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POTATO BLIGHT: A serious disease of potato caused by a fungus known as PHYTOPTHORA INFESTANS. Other plant disease are. Powdery mildews ( on grapes, rose, wheat & etc). Ergot of rye Red rot of sugar cane Potato will Cotton root rot Apple scab Brown rot of peaches, plums, apricots & cherries. ANIMAL DISEASES CAUSED BY FUNGI: Following are some of the fungal diseases in man. SKIN DISEASES: RING WORM & ATHELETE’S FOOT are superficial fungal infection caused by certain Fungi Inperfecti ORAL THRUSH: CANIDIA ALBICANS, a yeast causes oral & Vaginal thrush. ASPERGILLOSIS: Aspergillosis is the disease of ear & lungs caused by ASPERGILLUS. It occurs only in person with defective immune system such as AIDS & cause death. CANCER: Some strains of ASPERGILLUS FLAVUS produce one of the most carcinogenic ( cancer causing ) mycotoxins c alled AFLATOXINS.

ERGOTISM: Ergotism is caused by eating bread made from PUROLE ERGOT- Contaminated flour. The poisonous material in the ergot causes nervous spasm, convulsions, psychotic delusion & even gangrene. HISTOPLASMOSIS: Histoplasmosis is a serious disease of lungs caused by inhaling spores of a fungus, which is common in soil contaminated with bird’s feces.


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CHAPTER 9 KINGDOM - PLANTAE CLASSIFICATION OF KINGDOM PLANTAE: Kingatae is divided into tow sub-kingdom on the basis of presence or absence of vascular tissue (xylem and phloem). A - SUB-DIVISION - BRYOPHYTES (NON-VASCULAR): • Class Hepatica (Liverworts) • Class Musci (Mosses) • Class Anthroccrota (Hornworts) B- SUB-DIVISION - TRACHEOPHYTES: • • • • •

Class Psilopsida (Psilopsids) Class Lycopsida (Club Mosses) Class Sphenopsida (Horse Tails) Class Pteropsida (Ferns) ClassSpermopsida (Seed Plants)

CLASSES OF BRYOPHYTESBRYOPHYTES: 1-MUSCI (MOSSES): • Plants grow in a tight pack, in the form of mat, in order to hold one another up. • Mat of moss possess spongy quality and enables it to absorb and retain water. • Rhizoids are elongated cells or cellular filaments of mats which grip the substratum. • Photosynthesis occurs in upper part of the plant w/c has many small stem like and leaf like appendages. • E.g Funaria. 2-HEPATICAE (LIVERWORTS): • • • •

Usually present in tropical areas Plant body is divided into lobes somewhat of the lobed liver, of an animal. These plants are less fimiliar than Mosses. E.g Marchantia

3- ANTHROCERATAE:- (HORNWORTS): • These plants resemble w/t liverworts, but are differentiated by their sporophytes plants. • Sporophyte are elongated capsules that grow like horn from mat like gametophyte. • Sporophyte has stomata and chloroplast, performs photosynthesis • Sporophyte plant can survive even often the death of gametophyte due to presence of Meristem. • Meristem is a specialized tissue, which keeps on adding new cells in sporophyte plant. • Hornworts are the most advanced members of bryophytes. • E.g Arthroceros.


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CLASSES OF TRACHEOPHYTES: 1-PSILOPSIDA: • These are the fossil representatives of the vascular plants, belonging to “Silurain period” and “Devonian Period” • Sporophytes are simple dichotomously branching plants. • True leaves and true roots absent. • Underground stems that contain unicellular rhizoid similar to root hairs. • The aerial stems are green and carry out photosynthesis. • Lacking secondary growth due to absence of “Cambium” • Reproductive structure “Sporangia” develop at the tips of some of the aerial branches. • Meiosis produces haploid spores, within the sporangia. • E.g. Rhynia, Psilotum TemesipterisTemesipteris. 2-LYCOPSIDA(THE CLUB MOSSES): • These plants belong to middle Devonian and carboniferous periods. • They were very large trees that formed the earth’s first forests. • Only five living genera of this group are present. • Two members, selaginella and lycopodium are common in many areas of Pakistan • These plants have true branched underground roots. • True leaves also present w/c have arisen as simple scale like outgrowth (emergence) from the outer tissues of the stem. • Specialized reproductive leaves bearing sporangia on their surfaces, are present, such type of leaves are known as “Sporophylls”. • In some members, the sporophylls are collected on a short length of stem and form cone like structure “Strobilus”. • The cone is rather club-shaped; hence name “Club-Mosses” for the lycopsids. • Gametophytes plant may be homosporous or heterosporous. 3. SPHENOPSIDA (THE HORSE TAILS): • These plants belong to late Devonian and Carboniferous period. • Only one living member “Equisetum” commonly called “Horse-tail” exists today.


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• Ancient sphenopsids were large trees but now most of these are small (Less than one meter). • Coal deposits of today was formed from the dead bodies of those plants. • These plants possess true roots, stems and leaves. • Stems are hollow and are jointed, whorls of leaves occur at each joint. • Secondary growth absent, because modern species do not possess cambium. • Spore are born in terminal cones (Strobili) and all are alike (i.e. plants are homosporous) and give rise to small gametophytes that bear both archegonia and antheridia (i.e. the ***es are not separate). 4. PTEROPSIDA (THE FERNS): • These plants belong to Devonian and Carboneferous Period and then decline in Paleozoid Period. • They are very well developed plants having vascular system with true roots, stem and leaves. • Leaves are probably arisen from flattened web branched stems. They are large and provide much greater surface area for photosynthesis. • Leaves of Ferns are sometimes simple, but more often they are compound, being divided into numerous leaflets. • In most modern ferns of temperate regions, the stems are prostrate on or in the soil, and the large leaves are only part normally seen. 5. SPERMOSIDA (THE SEED PLANTS): • First appeared in late Devonian and became dominant in Carboniferous Period. • Gametophyte stage is even more reduced than in the ferns, and nonphotosynthetic or free-living. • The sperms of most modern species are not independent free-swimming flagellated cells. • Young embryo, is enclosed within a seed coat and can remain dormant for long periods. • Spermosida can be divided into two main sub-groups, which are as follows: (i) Gymnosperms (ii) Angiosperms

EVOLUTION OF LEAF: The leaf is the most important organ of a green plant because of its photosynthetic activity. Leaves are of tow types 1. Single veined leaves- Contain only one vein


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2. Poly veined leaves- Contain two or more veins 1- EVOLUTION OF SINGLE-VEINED LEAF: • It is assuming that a thorn like out growth emerged on the surface of the naked stem. • With an increase in size of the leaf, the vascular tissues were also formed for the supply of water and support to the leaf. • Another possibility is that a single veined leaf originated by a reduction in size of a part of the leafless branching system of the primitive vascular plants. - EVOLUTION OF POLY-VEINED LEAF: • These are the evolutionary modifications of the forked branching in the primitive plants. • The first step in the evolution of this leaf was the restriction of forked branches to a single plane. • The branching system become flat. • The next step in the evolution was filling the space b/w the branching and the vascular tissues. • The leaf so formed looked like the webfoot of a duck.

EVOLUTION OF SEED: Seeds are evolved from primitive spores. STEPS OF EVOLUTION: 1. PRIMITIVE SPORES: All spores of specie are nearly identical in size, structure and function. 2. HETEROSPORES: • There are many vascular plants that form two kinds of spores, these plants are said to be “Heterosporous” and spores are c alled “Heterospores.” • These spores on germination give rise to two different types of plants. (A) MALE SPORE: It produces sperm forming gametophyte plant. (B) FEMALE SPORE: It grows into egg forming gametophyte. 3. PROTECTION OF HETEROSPORES: • The two different kinds of spores are formed in two different kinds of sporangia. • Various enveloping structures develop in order to protect these spores. • Certain fern like plants first developed seed like structures, each of their sporangia, containing one or more female spores, was surrounded by little branch like out growth structure forming “Integument.” 4. PERSISTANCE OF FEMALE SPORES:


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• Instead of being shed from the sporangium, the female spores are retained and protected inside the integument. • The female spore develops into a tiny female gametophyte protected by the integuments. 5. FORMATION AND STRUCTURE OF SEED: • Seed is formed as the result of fertilization of male spore with this protected female spore. Immature seed is called “Ovule.” • Ovule is protected by integuments and it contains great quantities of food. • Ovule not only protects the female gametophyte from the environment but also provides food for the new off springs that is produced when the seed matures and germinate. The development of seed has given the vascular plants better adaptations to their environment.

RHYNIA (FIRST VASCULAR PLANT): • One of the most primitive vascular plant • It is an extinct genus, was named often the village “Rhynia of Scotland where the first fossils of Rhynia were discovered. • It belongs to Devonian period, which started about 400 million years ago. • The fossils of this plant are so well preserved that the stomata are still intact. STRUCTURE: • The plant body (Sporophyte) was simple. • It consisted of slender, dichotomously branched creeping rhizome, bearing erect, dichotomously branched aerial stem. • Instead of roots, rhizoids were given out from rhizome. • The aerial branches were leaf-less having terminal fusiform naked sporangia. MICROSCOPIC STRUCTURE: • The internal structure of branches show a solid central core of vascular tissues surrounded by Cortex. • The outer most layer is Epidermis having stomata. • The vascular tissue is differentiated into centrally placed xylem and surrounded phloem.

SPOROPHYTIC STAGES: • The large leafy plant (fern) is diploid sporophytic phase.


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• Spores are produced in sporangia (Reproductive structure) located in clusters on the underside of some modified leaves “Sporophyll.” • Most modern ferns are homosporous i.e. all these spores are alike. • Vascular sporophytes can live in drier places and grow bigger.

ALTERNATION OF GENERATION AND IT'S IMPORTANCE: When a gametophytic generation give rise to a sporophytic generation and a sporophytic generation give rise to a gametophytic generation. This phenomena is called alternation of generation. Alternation of generation is responsible for genetic variation and variation is essential for adaptation or adjustment to the changing environment. There fore alternation of generation is very important for survival of plants in the changing environment.

STRUCTURE OF OVULE: • Ovules are female part of flower, form seed after fertilization. • Microscopic study of an ovule reveals following structural features of an ovule. 1. FUNICLE: It is slender stalk of ovule through which it attaches to the placenta. 2. HILUM: It is the point of attachment of the body of the ovule to its funicle. 3. RAPHE: In the inverted ovule, the funicle continues beyond the hilum along side of the body of the ovule forming a sort of ridge, which is called the “Raphe.” 4. CHALAZA: The distal end of the raphe, which is the junction of integuments and the nucellus is called the “Chalaza.” 5. NUCELLUS: It is the main body of ovule. 6. INTEGUMENTS: Nucellus is surrounded by two coats called the “Integuments.”


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7. MICROPYLE : It is the small opening at the apex of integuments. 8. EMBRYO-SAC: It is a large, oval cell lying embedded in the nucellus towards the micropyle end. It is the most important part of the ovule as it bears the embryo.

FLORAL CHARCTERS: 1-INFLORESCENCE: Cyme sometimes helicoids.

2-FLOWER: Pentamerous, Bi***ual, Regular, Actinomorphic, Hypogynous. 3-CALYX: Five, united sepals. 4-COROLLA: Five petals, united, valvate aestivation. 5-ANDROCIEUM: Five stamens, Inserted on Corolla. 6-GYNOECIUM: Bicarpellary, Syncarpous (Carpels fused), Placentaion axile. 7-FRUIT: Capsule Berry or Xanthium. 8-SEED: Minute with abundant endosperm. FLORAL FORMULA: + , O , K(5) , A5, C

ECONOMIC IMPORTANCE Members of this family provide drugs and food. Some plants are poisonous and other are ornamental. This family is of great economic importance as it provides food, fodder, drugs and ornamentals.


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1-FOODER • Solanum tuberosum (Potato) • Lycopersicum esculentum (Tomato) • Solanum melongena (Brinjal) 2-CONDIMENTS • Fruit of capsicum • Capsicum frutenscens 3-EDIBLE FRUIT • Physalis (Cherry or Rasbhari)

4-DRUG YIELDING • Atropa belladonna (atropine) • Dotura (Daturine) • Used in severe cold and in eye diseases. • Sap of hanbane is used in dilating the pupils, white cherry is used an nerve tonic. 5-ORNAMENTAL: • Cultivated in gardens • Petunaia • Nicotiana • Cestrum Schizanthus • Brunfelsia solanum 6-CIGARETTE MAKING: • Nicotiania tobacum (Tobacco)

STRUCTURE OF OVULE • Ovules are female part of flower, form seed after fertilization. • Microscopic study of an ovule reveals following structural features of an ovule. 1. FUNICLE It is slender stalk of ovule through which it attaches to the placenta.


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2. HILUM It is the point of attachment of the body of the ovule to its funicle. 3. RAPHE In the inverted ovule, the funicle continues beyond the hilum along side of the body of the ovule forming a sort of ridge, which is called the “Raphe.”

4. CHALAZA The distal end of the raphe, which is the junction of integuments and the nucellus is called the “Chalaza.” 5. NUCELLUS It is the main body of ovule. 6. INTEGUMENTS Nucellus is surrounded by two coats called the “Integuments.” 7. MICROPYLE It is the small opening at the apex of integuments. 8. EMBRYO-SAC It is a large, oval cell lying embedded in the nucellus towards the micropyle end. It is the most important part of the ovule as it bears the embryo.


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CHAPTER 10 KINGDOM - ANIMALIA

Phylum Porifera (Sponges): Word Porifera is derived from Latin Porus – Pores and Ferro – to bear. The animals are also called “Sponges”. MAIN CHARACTERISTICS: Animals of this phylum show following important characters. NATURE: Most simple multicellular organisms. From evolutionary point of view they occupy a position between protozoa and true metazoa. HABIT AND HABITAT: Mostly marine but few in fresh water habitat. They are sessile, living attached to rocks, coral and other hard surfaces. SHAPE AND STRUCTURE: Their shape may be cylindrical, branching, globular, flat, bell shaped or cup shaped Some are dull in colour and most are brightly coloured The body is perforated by pores and canals. MICROSCOPIC STRUCTURE: Most of sponges contain following types of cell: a. PINACOCYTES: Forming the epidermis. b. POROCYTES: Form pores of the body wall. c. CHOANOCYTES: These are flagellated cells, form the internal lining of the body. These cells are strikingly similar to the choano flagellates. Much of the body is composed of jelly like matrix containing a skeleton made of Protein, CaCO3 or silica. Sponges are organized on cellular level, instead of a single cell carring on all the life activities.


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Sponges show cellular differentiation but little or no coordination o f cells to form tissues. They usually have an endoskeleton of separate spicules. They do not posses a head, an interior end, a mouth or gut cavity. They are sedentary organisms ranging in size from 1 to 200cm. DIGESTION: Digestion takes place with in the c ell. (Intracellular). PROCESS OF FEEDING, EXCRETION AND RESPIRATION: Sponges feed by filtering out bacteria and fine particles of organic matter from water. The flagella of “Choanocytes” beat and create a current of water. The water current also helps in respiration, removal of waste products and dispersal of gametes. REPRODUCTION: Reproduction is of both type asexual and s exual. Asexual reproduction is by means of “Buds” and “Gemmules formation”. Sexual reproduction is by means of sperm and ova. All sponges appear to be diploid and have the usual metazoan process of “Oogenesis” and “Spermatogenesis”. The eggs retained just beneath the choanocytes where they are fertilized by sperm from another sponge brought in with the c urrent of water. Fertilization is internal. LARVA: After cleavage, the larva escape from the parent to the open sea as a free swimming “Amphiblastula larva”. It finally becomes attached to the bottom by its anterior end. Reproduction is also by fragmentation. BODY CAVITY: Body cavity is known as “Spongocoel”. EXAMPLES: Common examples are 1. Sycon 2. Euplectella


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3. Euspongia

PHYLUM CNIDARIA (Coelenterata): This phylum include such simple animals having only two body layers. Hence these are called DIPLOBLASTIC MAIN CHARACTERS: HABIT AND HABITAT: They are aquatic animals, mostly marine and few fresh water forms. They are sedentary or free swimming and solitary or co lonial STRUCTURE: The cnidaria are metazoa having the simplest type of body wall consisting of two layers. The outer epidermis and the inner gastrodermis which lines the body cavity. In between the two layers lies the mesogloa, non-cellular jelly secreted by them. Cnidarians, due to their two layers body wall are termed as diploblastic animals. All other metazons possesses a third layer called mesoderm in their body wall, laying in between the epidermis and gastrodermis (Endoderm) and are therefore called Triploblastic animals. They have radially symmetrical body plan organized as a hollow sac. The mouth is surrounded by a circle of tentacles bearing cnidoblasts stinging cells containing nematocysts. They have central digestive cavity connected to the outside by mouth. STRUCTURAL TYPES: The Cnidarians are radially symmetrical and occur in two types of forms. (a) The polyp (b) The Medusa (A) POLYP: The polyp like Cnidarian for example sea anemone has a cylindrical body with a mouth directed upwards and surrounded by tentacles. The basal surface of the body is attached to the substratum. (B) MEDUSA: The medusa like Cnidarians jelly fish are umbrella like in appearance. Their oral surface, bearing the mouth is directed downwards. Whereas the aboral surface is directed upward. The medusoid Cnidarians are usually free swimming. PROCESS OF FEEDING AND DEFENCE: The Cnidarians feed mostly on animal diet. The food is digested in the gut and the waste products are expelled through the mouth.


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The Cnidarians so named, because they possess cnidoblasts bearing nematocysts which help in feeding and defence. REPRODUCTION: The Cnidarians reproduce by asexual as well as sexual methods. Polypoid Cnidarians possess a remarkable ability to regenerate. a. REGENERATION: If the oral part of the body is lost the remaining part regenerates the new mouth and the whole of tentacles. b. ASEXUAL REPRODUCTION: A sexual reproduction takes place by Budding. c. SEXUAL REPRODUCTION: The sexual reproduction takes place through male or female gametes which are usually produced by different parents. The gametes develop in the interstitial cells and aggregate in gonads which are located either in the epidermis or in the gastodermis. The fertilized egg gives rise to “Planula Larva” CLASSIFICATION OF CNIDARIA (COELENTERATA): The Phylum Cnidarians is divided into three classes: 1. Hydrozoa 2. Scyphozoa 3. Anthozoa 1. HYDROZOA: As the most primitive class of the Cnidarians, Hydrozoa is thought by some evolutionists to have given rise to both other classes. They show following characteristic features: They are mainly marine, but some are fresh water species Many species have both polyp and medusa For e.g: Hydra, Obelia and Physalia 2. SCYPHOZOA: Most of animals of this class are commonly called “Jelly Fish”. They are semitransparent and are of various colo urs. Most are of marine habitat. For e.g: Aurelia and Cyanea (largest Jelly Fish) 3. ANTHOZOA:


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These animals are mostly marine. Solitary or colonial Polyp forms are present. Medusa stage is absent. Gastrovascular cavity is divided into chambers, increase area for digestion. For e.g: Sea-anemones and Corals etc

PARASITIC ADAPTATIONS OF FLATWORMS: The parasitic adaptations of flatworms are as follows: i. They have thick body covering, which protects them from host body. ii. They have suckers, hooks and s pines for proper attachment and sucking of food material. These are the replacement of locomotory organs. iii. Their alimentary canal is reduced or absent in taenia solium (tap worm). Because they absorb food from host body. iv. Reproductive system is much developed and fertility rate is high to increase their number rapidly.

PRECAUTIONS AGAINST DISEASES: Flatworms are mostly parasites and cause many diseases. The precautions and control measures are as follows: i. Hygienic life should be maintained. ii. Sanitary conditions should be properly maintained. iii. Careful inspection of edible items is necessary. iv. Meat should be cooked properly to kill the parasites.

PHYLUM ASCHELMINTHES (Nematoda/Round worm): Nematoda are called Pin worm or round worms.

MAIN CHARACTERS: HABIT AND HABITAT: Nematoda have a very wide distribution and they seem to have mastered almost every habitat. Free living nematodes are found in the sea, fresh water or in the soil in all kinds of environment. There are also many parasitic nematodes found in all groups of Plants and animals. The Saprophagous species live in decomposing plant and animal bodies and in rotting fruits.


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NATURE: They have a bilaterally symmetrical, cylindrical body, glistening smooth surface. They are triploblastic. EXTERNAL FEATURES: They show no trace of segmentation. Most of the free living nematodes are less then a millimeter length. Some of the parasitic species attain a length of several meters e.g. Guinea worm (Dracunculus medinensis). They are usually long, round, tapered at both ends showing very little morphological diversity from species to species. The mouth of nematodes is modified for various modes of feeding such as cutting, tearing, piercing and sucking fluids from the host. Body is covered by cuticle, which moults only during the period of growth. INTERNAL FEATURES: The organs are packed in parenchyma when young, but later on it disappears in adult. So that organs lie in a fluid filled cavity. This cavity is termed as PSEUDOCOEL and it has not peritoneum. Muscles are only longitudinal. Excretory system has no flame cells. Alimentary canal is straight with ectodermal fore and hind gut and an endodermal mid gut. REPRODUCTION: Sexes are generally separate. Gonades are tubular and continues with their ducts. Female organs are usually paired and open by vulva. Male organs are single and open into a cloaca. The life cycle of Parasitic species involves one, two or more hosts EXAMPLES: Ascaris (Round worms), Hookworms and Thread worms etc.

Phylum Annelida (Segmented worms): The word Annelida is derived from latin Annelus meaning little ring. MAIN CHARACTERS: NATURE: Annelida are triploblastic, symmetrical, coelomata and segmented metozoa. HABIT AND HABITAT: Annelida are mostly aquatic, marine or fresh water, burrowing or living in tubes, some free living forms. EXTERNAL FEATURES


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The most important feature of annelida is their metameric segmentation. (External segmentation) Segmentation is indicated externally by circular constrictions or grooves on the body wall. Outer covering of the body is cuticle secreted by the underlying epidermis. Appendages, when present are unjointed. Locomotory organs are segmentally arranged, paired setae or chaetae. INTERNAL FEATURES: Body wall is contractile, consists of an outer epidermis, circular and longitudinal muscles. The gut, longitudinal blood vessels and the nerve cord extend throughout the body length, whereas other structures are repeated in each segment. Important character of annelida is the development of series of coelomic compartments in their body between the gut and the body wall. The Coelom is a cavity, which develop within the mesoderm and is lined by mesodermal cells. Segmented musculature plays an important part in locomotion of Annelids. SYSTEMS OF BODY: Alimentary canal is tube like extending straight from mouth to anus. Respiration through general body surface, by gills in some forms. Blood vascular system is closed type. Blood is red due to haemoglobin. Excretory organs are Nephridia usually one pair in each segment. Nervous system consists of dorsal brain and longitudinal ventral nerve cord. Sexes may be united or separate. Development is direct when sexes are united and indirect when sexes are separate. EXAMPLES: Nereis, Earthworm and Leeches etc. CLASSIFICATION OF PHYLUM ANNELIDA: Phylum Annelida is divided into four cl asses: 1. Polychaeta 2. Oligochaeta 3. Hirudinea 4. Archiannelida

Phylum Arthropoda (Jointed Appendages Animals): MAIN CHARACTERS: Arthropoda is the largest Phylum of the animal kingdom including 10, 00000 species of different types of animals. The word Arthropods is derived from Greek Arthos – Jointed and Podos – Foot.


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HABIT AND HABITAT: Arthropodes have undergone an adaptive radiation for aerial, aquatic, terrestrial and parasitic environment. They are widely distributed in each and every place of the world. NATURE: Arthropoda are “bilaterally symmetrical,” metamerically segmented metazoa. EXTERNAL FEATURES: Their body is covered by an exo-skeleton of “chitin” and protein. They possess paired jointed appendages. Their metamers are not alike but are specialized and their number is generally fixed. The head is well developed. INTERNAL FEATURES: Musculature is not continues but comprises separates striped muscles. The coelomic space in Arthropods is occupied by the blood vascular system and is thus called “Haemocoel.” Digestive tract is complete; mouth and anus lie at the opposite end of the body. Circulatory system is open with dorsal he art and arteries but without capillaries. Respiration through general body surface, by gills in aquatic forms, trachea or book lungs in terrestrial forms. Excretion by “Malpighian tubules” or Coelomoducts. Sexes are generally separate and sexual dimorphism is often exhibited by several forms. Fertilization is internal. Development is usually indirect through the larval stage. Nervous system of arthropods is quite similar to that of annelids and consists of dorsal anterior brain and a double ventral nerve cord. Phylum Echinodermata: GENERAL CHARACTERS: HABIT AND HABITAT: The Echinodermates are exclusively marine including the largest invertebrate “Giant Squids.” EXTERNAL FEATURES: Symmetry usually radial, nearly always pentamerous. Body shape is rounded to cylindrical or star like. Surface of the body is rough. Body wall consists of an outer epidermis, a middle dermis and inner lining of peritoneum. INTERNAL FEATURES: Endoskeleton consists of closely fitted plates forming shell usually called “THECA,” may be composed of separate small “OSSICLES.”


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Coelom is spacious, lined by peritoneum and occupied mainly by digestive and reproductive systems. Presence of “Water Vascular System” is most characteristic feature. Alimentary tract is usually coiled. Circulatory or Haemal or blood lacunar system is typically present. Excretory system is wanting. Nervous system is primitive, consists of ganglionated nerve cord. Sense organs are poorly developed. Sexes are usually separate. Reproduction is usually sexual, fertilization is external. WATER CANAL SYSTEM: Water canal system is unique in possessing an internal closed system of canals containing a watery fluid. REGENERATION: Regeneration of lost part is common IMPORTANCE OF WATER CANAL SYSTEM: These canals are provided with tubular protrusions called “Tube Feet,” which serve a number of functions like locomotion, anchoring to hard surfaces, grabbing the prey, diverting food particles towards mouth and in some cases also respiration. The watery fluid is drawn from the surrounding water through a perforated disc called the “Madreporite.” EXAMPLE: Star Fish, Brittle stars, Sea urchins, Sea-cucumbers, Sea-Dollar, Sea-lilies and Feather stars. LARVA: Bipinnaria larva

Phylum Chordata: It includes animals, which exhibit great difference of anatomy, physiology and habits. These animals are highly developed. GENERAL CHARACTERS: The chordate animals at some time in their life history exhibit the following diagnostic characters: 1. NOTOCHORD: It is an elastic, solid, skeletal rod lying below the nerve cord and above the alimentary canal. It serves as a primitive internal skeleton and acts as a rigid axis. It may persist throughout life or it may be replaced partially or completely by a backbone or vertebral column.


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2. DORSAL HOLLOW NERVOUS SYSTEM: There is a dorsal, hollow, fluid filled nerve cord. It is formed by enfolding of a mid-dorsal strip of ectoderm and it generally sinks below the surface. It lies above the notochord and outside the coelom. It persists throughout life in most chordates, but in a few it degenerates before maturity. 3. GILL CLEFTS: These are paired openings leading from the Pharynx to the exterior. Such gill clefts appear during the development of every chordate, but in many aquatic forms they are lined with vascular lemallae, which forms gills for respiration. In terrestrial chordates, which never breath by gills, gill clefts are present during early development but later on, they disappear. 4. PHA-RYNGEAL POUCHES: All the chordates have paired pharyngeal pouches at some stage of their life cycle. These extend from laterally from the anterior part of the digestive tract towards the body wall. OTHER FEATURES: Chordates are triploblastic. They are bilaterally symmetrical. True coelom is found. They are found in almost all the habitats of the World.

CLASS CHONDRICHTHYES (CARTILAGE FISHES): Alternate name is “Class Elasmobranchi.” Usually includes marine fishes with endoskeleton of cartilage (soft bone). Skin contains sharp tiny enamel coated denticles called “Placoid Scales,” which form exoskeleton. · Mouth is ventral in position and tail fin is “Heterocercal.” Five exposed gill slits, which are not covered over by a gill cover. Common examples are Skates, Sharks, Rays and Scoliodon (Dog Fish)- a small Shark etc.

CLASS OSTEIOCHTHYES (BONY FISHES): Alternate name is “Teleostom,” actually the largest class of chordates. Includes marine and fresh water fishes. Mouth is present at anterior tip. Endoskeleton in these fishes is made up of hard bone while exoskeleton is made up of thin bony plates, which are known as “Cycloid” or “Ctenoid scales.” Gills are covered over on each side by a gill cover c alled “Operculum.” An air bladder is present which acts as a hydrostatic organ. Tail fin is usually “Homocercal or Diphycercal.” Common e.g are Eel, Sea-Horse, Flying Fish, Globe Fish etc


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LUNG FISHES: Zoogeographically important fishes, belonging to group “Dipnoi, included in Class Osteiochthyes. Only three living genera. They respire by gills and by lungs during drought period (Lungs-Modified air bladder). Limited distribution in South America, Africa and Australia. E.g: Protopterus (African Lung Fish).

CLASS AMPHIBIANS: This class includes the animals that came out of the water and established a successful life on land. They took advantages of the improved possibilities by remaining close to water, by keeping a soft and moist skin, by developing lungs and by evolving a bony skeleton with a strong vertebral column and four legs. They cope with seasonal changes by burrowing during extreme cold and save water by sealing themselves in a mucous envelop on dry land. The bony endoskeleton is the main body support. The notochord is absorbed during development Breathing is mostly by means of skin and also lung, and also by lining of buccal cavity. In larva the breathing is mostly by means of external or internal gills. The circulatory system shows a three chambered heart, with two atria and one ventricle. The amphibians are “Cold Blooded” (Poikilothermic) that is having internal temperature that very with the environment. Eggs and sperms are laid in water and fertilization is external. E.g: Frog and Toads, Salamanders, Newts, Mud puppies etc.

CLASS REPTILIA: GENERAL CHARCTERS: The earliest reptiles evolved from the amphibians. HABIT AND HABITAT: Reptiles are generally well adapted to life on land, in semi-dry, completely dry and even desert habitat. NATURE: All reptiles lay their eggs on land. They are cold-blooded animals and are less active during low temperature. STRUCTURAL FEATURES: They possess dry skin covered with epidermal scales. In some lizards and crocodiles, small bony plates develop below the epidermal scales.


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The skeleton is built on the same plane as that of amphibians, but is much stronger to support their body weight. Respiration takes place exclusively through lungs. Heart is three chambered, two auricles and one incompletely divided ventricle. (In Crocodiles, the ventricle is completely divided into two chambers.) The excretion takes place through kidneys. The reptiles secrete much of their waste products in form of non-toxic “Uric-Acid.” REPRODUCTION: In most reptiles fertilization is internal. Eggs are provided with a shell and are laid on land. The early development of embryo takes place on the large quantities of yolk and albumin present in the egg. Due to the presence of a protective membrane called “AMNION” in the egg, reptiles are included in the “Amniota Group” of Vertebrates. EXAMPLE: Alligators, Crocodile, Snake, Turtle and Gecko etc.

CHARACTERS OF CLASS AVES: HABIT AND HABITAT: The birds live from pole to pole in all type of ecological zones. They all breed on land.

FLIGHT AND ADAPTATION: Feathers differentiate birds from all other vertebrates. Feathers originated as extraordinary development of Reptilian scales. Instead of growing all over the body and spreading evenly, the feathers grow in definite tracts. The feathers play an important role in the thermoregulation of birds. They trap air, which is a bad conductor of heat and so prevent loss of body heat. To fly efficiently the birds have reduced their body weight in a variety of ways. Many bones become hollow, thin and light. Synsacrum and pygostyle are formed by the fusion of vertebrae and give strength to skeleton. Birds possess strong muscles to control the use of wing in flight. ADAPTATION FOR COMMUNICATION: They possess large eyes with well-developed sight. The birds communicate with members of their species with sound signals for which the sense of hearing is well developed. STRUCTURAL FEATURES: The great mobility of neck is helpful in feeding, nest building, preening and defence. There are developed a number of types of bills according to their feeding habits.


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The digestive system of birds is compact and can accommodate large quantity of food. The food is stored for a short period in the crop. “Gizzard” possess thick muscular wall with horny lining, small stones swallowed by birds are passed on the gizzard for grinding the food. The “Syrinx” or sound-producing organ is found in no other vertebrate except the birds. It is located at the junction between the trachea and the paired bronchi. The lungs of birds are small, solid, spongy and slightly distensible. They are in contact with a number of air sacs. MIGRATION IN BIRDS: A large number of species of birds exhibit a deep-rooted phenomenon of migration, during which they travel long distances from their summer breeding homes towards areas of warm climate.

SUB-CLASSES OF AVES: There are two main sub-classes of aves, which are: i) Sub-Class Ratitae (Flightless Birds) ii) Sub-Class Carinatae (Free-Flying Birds)

I) SUB CLASS RATITAE (FLIGHTLESS BIRDS): This sub-class includes modern big sized flight less birds. They comparatively have heavy weight and their wings are either vestigial or rudimentary. They have a flat sternum without keel. Their flight muscles are poorly developed. The distribution of these birds is restricted to few areas of the World. E.g: Ostrich, Rhea, Emu, Cassowary, Kiwi and Penguin. II) SUB-CLASS CARINATAE (FREE FLYING BIRDS): In this sub-class modern flying birds are included. They are usually small, light weight birds with highly developed wings and feathers with interlocking system. They possess sternum with a crest like keel to accommodate the hightly developed pectoral flight muscles. The flying birds are distributed all around the World. E.g: Sparrow, Pigeons, Myna, Bulbul, Hoopoes, Crow, Doves, Parrots, Fowls, Cuckoo and Ducks etc.

CLASS MAMMALIA: Early mammals are originated from reptiles. The distinctive characteristic of mammals are at the highest grade of development in animal kingdom. GENERAL CHARACTERS: HABIT AND HABITAT:


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Mostly terrestrial, a few aquatic.

NATURE: They are warm-blooded animals. They can maintain a fairly high body temperature and so can successfully survive in colder areas of the world. TEMPERATURE REGULATION: Heat is generated by high metabolic rate of their body and is lost by increasing blood circulation in the skin and evaporation of sweat. The mammalian body temperature is maintained at 35 C-40 C. ˚

˚

APPARENT FEATURE: All mammals possess hair on skin. Sweat glands and sebaccous glands are present on sk in. Mammary glands secrete milk in females. External ears (Pinna) are present. Teeth are heterodont i.e. not uniform. The different types of teeth are: Incisors, Canine, Premolars, Molars. SKELETAL SYSTEM: Skull with two occipital condyles is present. Lower jaw is composed of single bone on each side. Vertebrae are “Gastrocentrous,” composed of three pieces i.e. the centrum and two epiphyses. Digits of fore and hind limbs are usually five. Cervical (Neck) vertebrae are seven. INTERNAL FEATURES: A thick muscular septum “Diaphram” is present between abdomen and thoracic cavity. Heart is four-chambered. R.B.Cs are non-nucleated. Brain with four optic lobes. Kidney is metanephrous. The stomach is simple sac but rarely complicated. REPRODUCTION Mammals give birth to young ones (Viviparous), which are nourished by parents. Except Prototherians that lay eggs. Fertilization is internal. Development of eggs occurs in the uterus of female, where the developing embryo develops relationship with mother (Placenta). After the birth of the child, the mother nourished her young ones. CLASSIFICATION OF CLASS MAMMALIA: Mammals are divided into three sub-class:


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1. SUB-CLASS PROTOTHERIA: Includes the egg laying mammals. For example Duck billed, Echidna (Spiny anteater). 2. SUB-CLASS METATHERIA: Includes the pouched mammals, also known as “Marsupial mammals.” For example Kangaroo, Koala Bear and Opossums etc. 3. SUB-CLASS EUTHERIA: Includes the placental mammals. For example Monkey, Cow, Elephant, Cat, Dog, Bat, Whale and Human being etc.


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CHAPTER 11

BIOENERGETICS PHOTOSYNTHESIS: The process by which plants manufacture their own organic compounds by taking inorganic compounds from their surroundings, in the presence of sunlight, is called photosynthesis. LIGHT INDEPENDENT REACTION (Dark reaction): (CALVIN-BENSON CYCLE): The dark reaction does not require light and may take place both in light and dark during night. In dark reaction the hydrogen which is separated from water combines with carbon of CO2 and forms simple carbohydrates by the help of energy rich compound ATP. In dark reaction chemical energy is used in the form of ATP and NADPH + H*. Malvin calvin worked on the pathway of carbon to carbohydrates. Calvin got noble prize on his work. The cycle of chemical reactions in dark reaction is known as Calvin-Benson cycle (Reductive Pentose phosphate cycle. It is also called C3 Photosynthetic carbon reaction cycle. The calvin cycle actually consists 13 main reactions which are catalysed by 11 enzymes. FERMENTATION: Anaerobic respiration (without O2) is also called fermentation. When ethyl alcohol is formed in this process, it is called anaerobic respiration. When lactic acid is formed in the process, it is called lactic acid fermentation.

ECONOMIC IMPORTANCE OF FERMENTATION: The economic importance of fermentation is as follows: 1. By this process many chemical products are prepared, such as ethyl alcohol, lactic acid, propionic acid and butanol. 2. It is used in brewing industry. 3. It is used in diary industry, in the formation of curd, cheese, butter, etc. 4. It is used in the preparation of wines and beers. Wines are produced from fruits like grapes. Beers are produced from malted cereals, e.g. Barley. 5. Yeast is used in bakeries to prepare many items, such as bread. 6. Lactic acid is used to produce flavour to the yoghurt and cheese. Lactic acid prevents the spoilage of diary products.


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7. Lactic acid is also used to produce flavour in pickles. 8. Fermentation is also used in the preparation of acetone and other industrial solvents.

GLYCOLYSIS: The initial stage of respiration is called glycolysis in which O2 is not used. It is common both in aerobic and anaerobic respiration. In this process carbohydrates are changed into a 3-carbon compound, the pyruvic acid. The reactions of glycolysis are as follows: 1. The glucose is converted into glucose-6-phosphate by the utilization of an ATP compound. (an energy rich compound). 2. Glucose-6-phophate is changed into fructose 1-6 biphosphate by the arrangement of carbon atoms. 3. Fructose-6-phosphate is converted into fructose 1-6 biphosphate by the use of an ATP compound. 4. Fructose 1-6 diphosphate is divided into two 3-carbon compounds, 3phosphoglycer-aldehyde and bihydroxy acetone-phosphate. 5. 3-phospho-glycer-aldehyde is changed into 1-3 biphospho glyceric acid. 6. 3-phosphoglyceric acid is c hanged into 2-phospho-glyceric acid. 7. 2-Phospho glyceric acid is changed into 2-phosphoenol-pyruvic acid. 8. In the presence of ADP 2 phosphoenol pyruvic acid is converted into pyruvic acid. ADP is transferred into ATP.

THE KREB CYCLE (TRICARBOXYLIN CYCLE): In the presence of sufficient amount of oxygen the pyruvic acid is oxidized. In the presence of coenzyme A it releases CO2 and changes into acetyle coenzyme A. In this process two hydrogen are also removed which are accepted by NAD molecules to form NADH2. The acetyl coenzyme A enters the Krebs cycle. The details of Krebs cycle are as follows:

1. In the first reaction of Krebs cycle the acetyl-coA combines with oxalo-acetic acid, a 4-carbon compound and changes into citric acid. In this reaction coenzyme A is released and one molecule of water is used.

2. Citric acid is converted into cis-aconitic acid in the presence of enzyme by dehydration in which a water molecule is released.

3. Cisaconitic acid is converted into isocitric acid. In this reaction a molecule of water is used.


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4. Isocitric acid produces oxalo-succinic acid by the liberation of hydrogen. It combines with NAD to form NADH2.

5. Oxalo-succinic acid produces compounds, a-keto-glutei acid.

CO2

and

changes

into

5-carbon

atoms

6. The a-ketogluteric acid is changed into succinyl CoA. In this process two hydrogen are also liberated and combine with NAD to form NADH2.

7. From succinyl CoA compound CoA is released and it is converted into succinic acid. In this process ATP compound is formed by the phosphorylation of ADP.

8. Succinic acid is oxidized to form fumaric acid. In this process instead of NAD another compound FAD (Flavin adenine dinucleotide) is used for oxidation and to receive two hydrogen atoms from succinic acid.

9. Fumaric acid is changed into malic acid by the release of H2O.

10. In the final phase of citric acid cycle the malic acid is converted into oxaloacetic acid. In this process two hydrogens are also liberated and combine with NAD, which is changed into NADH2.

The oxaloacetic acid again picks up another acetyle CoA and the Krebs cycle then starts once again. The cycle continues as long as acetyle-CoA is available.

TROPHIC LEVELS: Food is very important for all living organisms because it provides energy. In an ecosystem the flow of energy occurs through a chain, for example plants are eaten by herbivores and the herbivores are eaten by carnivores, thus the food manufactured by plants travel from producers to primary consumers i.e. herbivores and then to secondary consumers i.e. carnivores. "This stepwise process through which food energy moves, with repeated stages of eating and being eaten is known as food chain." E.g. Grass---------->Sheep----------->Man Food chain represents various levels nourishment. These levels are called trophic levels. The green plants occupy the first trophic level. It is the primary producer level. The herbivores form the second level o r primary consumer level. These trophic levels are the arranged in a systematic manner plants --- primary consumers--> secondary consumers --> tertiary consumers --> bacteria (decomposers). In each step the number and mass of organisms is limited by the amount of energy available. Because some energy is lost in the form of heat, thus the steps become progressively smaller near the top. These trophic levels are shown graphically by means of pyramids, called ecological pyramids. In the


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pyramid the producer level constitute the base of the pyramid and tertiary consumers or decomposers level make the apex.

PYRAMID OF ENERGY: This pyramid shows the rate of energy flow or productivity at successive trophic levels. This pyramid is always upright and it gives the best picture of overall nature of the ecosystem. It indicates the amount of energy available for successively higher trophic levels. In most of the cases there is always a gradual decrease in the energy content at successive trophic levels from the producers to various consumers.


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CHAPTER 12 NUTRITION NUTRITION: The process by which living organisms obtain energy to perform all their functions of life to make important materials and to maintain their structure is called nutrition.

TYPES OF NUTRITION: Plants can be divided into two groups on the basis of their mode of nutrition. 1. Autotrophic Nutrition 2. Heterotrophic Nutrition 1. AUTOTROPHIC NUTRITION: Autotrophic nutrition is the type of nutrition in which organic compounds are manufactured from available inorganic raw material taking from surroundings. In autotrophic nutrition, the nutrients do not require to be pretreated or digested before taking them into their cells. On the basis of source of energy, autotrophic nutrition can be sub-divided into following sub-types. (I) Phototrophic nutrition (II) Chemotrophic nutrition I. PHOTOTROPHIC NUTRITION: The type of autotrophic nutrition is which organic molecules are manufactured from simple inorganic molecules by using light energy as a source is called Phototrophic Nutrition. (II) CHEMOTROPHIC NUTRITION: The mode of autotrophic nutrition in which organic molecules are manufactured from simple inorganic molecules by using energy produced by the oxidation of certain inorganic substances such as ammonia, nitrates, nitrites, ferrous ions, H2S and etc. This type of nutrition is called CHEMOTROPHIC NUTRITION and process of manufacturing food is called CHEMOSYNTHESIS. 2. HETEROTROPHIC NUTRITION: Plants which are not capable of manufacturing their own organic molecules entirely or partially depend for these organic molecular are called "HETEROTROPHIC PLANTS".


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CLASSIFICATION OF HETEROTROPHIC PLANTS: On the basis of type of organisms on which heterotrophic plants depend, they can be classified into following two classes. 1. Parasitic plants or Parasites 2. Saprophytic plants or Saprophytes 3. Carnivorous plants or insectivorous plants

1. PARASITIC PLANTS OR PARASITES: Those heterotrophic plants which depend on living plants and animals for their nutritional requirements are known as PARASITES. TYPES OF PARASITES: Parasitic plants can be divided into following types. a. Obligate parasites. b. Facultative or partial parasites. a. OBLIGATE PARASITES: Those parasites which depend for their nutrition entirely on other living organisms. They are also called total parasites. CLASSIFICATION ANGIOSPERMS:

OF

OBLIGATE

PARASITES

OR

TOTAL

PARASITIC

Total or Obligate parasitic angiosperms are broadly classified into i. Total stem parasite ii. Total root parasite i. TOTAL STEM PARASITES: Those parasitic plants which depend entirely on the stems of other plants are called “Total stem parasites. These plants send HAUSTORIA (specialized structures for absorbing nutrients in parasitic plants) inside the tissue of host. The xylem of parasite comes in contact with xylem of host and phloem of parasite to phloem of host. Through xylem it sucks the water and nutrients, through phloem prepared organic material. The host plant eventually dies off due to exhaustion. ii. TOTAL ROOT PARASITES: Those parasitic plants which suck their nutritional requirements from the roots of host are called total root parasites.

b. PARTIAL PARASITES:


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“Those parasite plants which depend for their nutritional requirements partially on other living organisms are called Falcultave or partial parasites." CLASSIFICATION OF PARTIAL PARASITIC ANGIOSPERMS: Partial parasitic angiosperms can be broadly classified into: i. PARTIAL STEM PARASITE ii. PARTIAL ROOT PARASITE

i. PARTIAL STEM PARASITES: Those partial parasites whose haustoria penetrate in the stem of the host and suck their nutrition from vascular tissues of stem are called "PARTIAL STEM PARASITE". LORANTHUS, is a partial stem parasite. It has thick green leaves, a woody stem and elaborated haustorial system. It can manufacture some of its food with the help of nutrients and water absorbed from host plants. The seeds get stuck upto the stem of host plant and germinates sending its haustoria in the tissues of the host. ii. PARTIAL ROOT PARASITES: These plants get their food partially from the roots of other plants. For example sandal wood tree. Its seedling does not grow independently. Its roots absorb nourishment from the roots of other plants.

2. SAPROPHYTES PLANTS: Those plants which depend for their nutrition on dead or rotten organic remains of plants or animals are called as "SAPROPHYTES PLANTS". TYPES OF SAPROPHYTES: Saprophytes can be divided into two types: i. Total Saprophytes ii. Partial Saprophytes i. TOTAL SAPROPHYTES: Those plants which depend entirely for their nutrition on dead organic matter are called Total Saprophytes. ii. PARTIAL SAPROPHYTES: Those plants which depend partially on dead organic matter are called Partial Saprophytes. 3. CARNIVOROUS OR INSECTIVOROUS PLANTS:


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The plants which have as their prey, insects and small birds are called Carnivorous plants. It is a special mode of nutrition in partially autotrophic and partially heterotrophic plants. Partially autotrophic and partially heterotrophic plants are carnivorous, which possess the green pigments and can manufacture CHO but are not capable of synthesizing nitrogenous compounds and proteins. For their nitrogen requirement, carnivorous plants have to depend on insects, which they catch and digest by specific devices developed in them. J.D. Hooker suggested that the digestion of carnivorous plants is like that of animals. 1. PITCHER PLANT: In Pitcher plant leaf is modified into pitcher like structure which is insect trapping organ. EXAMPLES: Common examples are : 1. Nepenthes 2. Sarracenia 3. Cephalotus 4. Neliamphora 5. Darling tonia

2. DORSERA INTERMEDIA OR SUNDEW: This plant has half a dozen prostrate radiating leaves, which bear hair like tentacles each with gland at its tip. The insects attracted by plant odour are digested.

3. DIONAEA MUSCIPULA OR VENOUS FLY TRAP: Most well known of all carnivorous plants. It has a resette of prostrate radiating leaves with inflorescence in the centre. The petiole of leaf is winged and lamina has two halves, with mid-rib in the centre. Each half has 12-20 teeth. In the centre of dorsal surface of lamina are numerous secretory glands, three hairs projecting out, which are sensitive to touch.

4.ALDROVANDA (WATER FLY TRAP): It is a root less aquatic plant with floating stem. It has ressettes of modified leaves, which have two lobed mobile lamina having teeth at the margin and sensitive jointed hairs and glands on the surface. 5. UTRICULARIA OR BLADDER WORT: It is a root less plant having branched slender stem. Leaves are also much divided and some leaflets are modified into bladder like traps of about 1/16 to 1/8 inches in diameter.


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ZOOLOGY PART PARTS OF ALIMENTARY CANAL: The alimentary canal of man consists of following parts: 1. Mouth and buccal cavity 2. Pharynx 3. Oesophagus 4. Stomach 5. Small intestine This part is further divided into (i) Duodenum, jejunum, (iii) lleum. 6. Large intestine This part is further divided into three portions. (i) colon, (ii) caecum, (iii) rectum.

TEETH OF MAN AND DENTAL FORMULA: There are different types of teeth in man incisors, canines, premolars and molars. Incisors and canines are the anterior teeth while premolars and molars are the posterior ones. They change the food into small particles. Man has two sets of teeth, it is called diphycodont. One set is of milk teeth, deciduous, these are replaced by another set, permanent teeth. The teeth are of different shapes and sizes, it is called heterodont. These teeth are embedded in the gums, it is called thecodont. The man has 8 incisors, 4 canines, 8 premolars and 12 molars. The human dental formula is (i 2/2, c 1/1, pm 2/2, m 3/3) × 2 = 32

DENTAL DISEASES AND PLAQUE: A soft thin film of food debris, mucin and dead epithelial cells deposited on teeth, providing medium for growth of bacterias. Plague plays an important role in development of dental caries, periodontal and gingival disease. Calcified plaque forms dental calculus.

1. PERIODONTAL DISEASES: Accumulation of plaque causes inflammation of gums. Continuous inflammation may spread to the root of tooth and destroy peridental layer. Eventually tooth becomes loose and falls off or may have to be extracted.

2. DENTAL CALCULUS:


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Plaque combine with certain chemicals in saliva which become harden and calcified forming deposits of calculus which cannot be removed by brushing.

3. DENTAL CARIES: When bacteria of plaque converts sugar of food into acid, the enamel (hardest substance of body, covers dentin of crown of teeth) is dissolved slowly. When dentine and pulp are attached, produce toothache and loss of teeth. FACTORS OF DENTAL CARIES: 1. Prolonged exposure to sugary food stuff. 2. Disturbance of saliva composition 3. Lack of oral hygiene 4. Low levels of fluoride in drinking H2O

DIGESTION IN SMALL INTESTINE OF MAN: SMALL INTESTINE: The small intestine is a coiled tube approximately 6 meters long and 2.5 cm wide, leading from stomach to large intestine. It fills most of the abdominal cavity. It consists of three parts: 1. Duodenum 2. Jejunum 3. Ilium

1. DUODENUM: It begins after pyloric stomach and ends at jejunum. Its length is about 30cm. Pancreatic juice from pancreas by pancreatic duet and bile from gall bladder by common bile duct act on chyme from stomach. Both ducts open via a common opening in duodenum. BILE: There are two bile pigments, red pigment is bilirubin and green is biliverdin. These are produced by the breakdown of haemoglobin of ruptured RBCs in the liver. PANCREATIC JUICE: Pancreatic juice is produced in pancreas by its exocrine function and secreted via pancreatic duct. It is a colourless fluid. Pancreatic juice contains following enzymes. a. TRYPSIN (PROTEASE):


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It is secreted in an inactive form called Trypsinogen which is activated by action of an enzyme produced by duodenum called enterokinase. b. CHYMOTRYPSIN: It is also secreted in inactive form, Chymotrypsinogen which is converted into chymotrypsin by action of Trypsin. c. AMYLASE: It is similar to salivary amylase. It acts on polysaccharides (Glycogen and Starch) and convert them into maltose (a disaccharide). d. LIPASE: It acts on emulsified fat droplets. It splits off lipid into fatty acid and glycerol, hance the digestion of fat is completed in duodenum. 2. JEJUNUM: It extends from duodenum to illeum. It is 2.4 meters long. Here the digestion of food is completed. 3. ILIUM: It is the last and longest part of small intestine. Its length is about 3.6 meters long. It contains digested food in true solution form.

MECHANISM OF ABSORPTION: Major function of ileum is absorption of digested food, which is facilitated by highly folded inner wall of intestine with villi on their surfaces. This increases the absorptive area. Villi are able to move back and forth due to muscle fibers in them. The monosaccharide and A.As are absorbed into blood capillaries by Diffusion or Active Transport. Fatty acid and glycerol enter epithelial cells of villi, covert into triglycerols and enters Lacteals and pass into blood stream.

PANCREAS: A large elongated gland situated transversely behind the stomach, between spleen and duodenum. DISORDERS OF Gastro Intestinal Tract:

(1) DIARRHOEA: Abnormal frequency and liquidity of fecal discharges. It is the rapid movement of fecal matter through large intestine. CAUSES:


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ENTRITIS: It may be caused by infection of intestinal wall (mucosa) by a virus or bacteria. Due to infection, mucosa becomes irritated and motility of intestinal wall increases. CHOLERA: Cholera is a bacterial disease caused by VIBRIO CHOLERA. It can cause diarrhoea. It causes extreme amount of HCO3- (bicarbonates ion) and Na and H2O to be secreted in faeces. It may causes death. PSYCOGENIC DIARRHOEA: It is caused by nervous tension. In the young and elderly, diarrhoea may lead to a serious depletion of H2O and inorganic salts. (2) DYSENTARY: Acute inflammation of intestines especially of the colon. CAUSES: PROTOZOA. (like amoebic dysentery) PARASITIC WORMS. BACTERIA. (like bacillary dysentery) CHEMICAL IRRITANTS. (3) CONSTIPATION: Infrequent or difficult evacuation of faeces. OR Slow movement of faeces through large intestine. Faeces becomes hard due to long time available for H2O absorption.

CAUSE: Irregular bowel habits that have developed through a life time of inhibition of normal defection reflaxes. (4) PILES: Also called HAEMORRHOIDS Varicose dialatation of veins occurring in relation to anus, resulting from a persistence increase in pressure. (5) DYSPEPSIA: Impairment of the power or function of digestion, usually applied to epigastria discomfort following meals.

CAUSE: May be due to peptic ulcer.


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(6) PEPTIC ULCER: Since pepsin, is a protein digesting enzyme, it may digest the stomach wall, the first part of duodenum or rarely lower part of oesophagus where stomach juices frequently refluxes. This condition is called Peptic U lcers. (7) FOOD POISONING: Also called GASTRO-ENTRITIS CAUSES: INFECTION: By bacteria, virus, protozoa. ‘Salmonella’ species are very common. (8) MAL NUTRITION: Any disorder of nutrition due to unbalanced diet or due to defective assimilation or utilization of foods. An organism may be deficient or may receives excess of one or more nutrients for a long period of time. (9) OBESITY AND OVER WEIGHT: Increase in body weight beyond the limitation of skeletal and physical need as the result of accumulation (excessive) of fat in the body. It is the most common nutritional disorder. It is most prevalent in middle age. It may be hereditary or family tendency over weight results in rate of mortality. (10) ANOREXIA: Loss or lack of appetite for food is called Anorexia. ANOREXIA NERVOSA: An eating disorder affecting young females, characterized by refusal to maintain a normal minimal body weight, intence fear of gaining body weight, intense fear of gaining weight or becoming obese. Sometimes accompanied by spontaneous or induced vomiting. (11) BULIMIA NERVOSA: Exclusively found in women and the age of onset is slightly older than for anorexia. Recurrent episodes (bouts) of binge (uncontrolled) eating. Lack of self control over eating during binges. Attacks occur twice a week and involve rich foods such as cakes and chocolates and dairy products.


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CHAPTER 13 GASEOUS EXCHANGE RESPIRATORY ORGANS OF COCKROACH TRACHEAL SYSTEM: Cockroach has evolved a special type of invaginated respiratory system called Tracheal system, especially adopted for terrestrial mode of life and high metabolic rate of insects. STRUCTURAL CONSTITUENTS OF TRACHEAL SYSTEM: 1. Trachea 2. Spiracles 3. Tracheoles 1. TRACHEA: Tracheal system consists of number of internal tube called Trachea which are the connection between the spiracles and tracheal fluid. 2. SPIRACLES: Laterally, trachea open outside the body through minute, slit like pores called as spiracles. There are 2 pairs of spiracles on lateral side of cockroach. 2 lie in thoracic segments and 8 in first abdominal segments. 3. TRACHEOLES: On the other side, trachea ramifies throughout the body into fine branches or tracheols. Tracheoles finally end as blind, fluid filled fine branches which are attached with cells of tissue. Both the trachea and tracheoles are lined internally by thin layer of cuticle. MECHANISM OF RESPIRATION “INFLOW OF OXYGEN”: The cockroach takes in air directly from the atmosphere into the trachea through spiracles. This air diffuses directly into fluid filled tracheoles through which diffuse into the cells of tissues. Hence the blood vascular system of cockroach is devoid of hemoglobin. OUTFLOW OF CARBONDIOXIDE: Removal of CO2 from cells of body is largely depended upon plasma of blood, which takes up CO2 for its ultimate removal through body surface via the cuticle.

RESPIRATORY SYSTEM OF FISH MAIN RESPIRATORY ORGAN:


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In fish, main respiratory organs are “Gills”. They are out growth of pharynx and lie internally with in the body so that they are protected from mechanical injuries. INTERNAL STRUCTURE OF GILLS: Each gill is highly vascular zed structure. It is composed of 1. Filaments 2. Gill bar or Gill arch 3. Lamella

1. FILAMENTS: Each gill is composed of two rows of hundreds of filaments, which are arranged in V-shape. 2. GILL BAR OR GILL ARCH: Filaments are supported by a cartilage or a long curved bone the gill bar or gill arch. 3. LAMELLA: Lamella is a plate like structure which is formed by in folding of filaments. Lamella greatly increase the surface area of the gill. Each lamella is provided by a dense network of capillaries. OPERCULUM (IN BONY FISHES): Gills are covered on each side by gill cover called “operculum” MECHANISM OF VENTILATION: In bony fishes, ventilation is brought about by combined effect of mouth and operculum. Water is drawn into the mouth. It passes over the gills through pharynx and ultimately exists at the back of o perculum through open operculur valve. Water is moved over the gills in a continuous unidirectional flow by maintaining a lower pressure in operculur cavity than in buccopharynx cavity. COUNTER CURRENT FLOW OF WATER AND BLOOD: Gaseous exchange is facilitated in gills due to counter current flow of H2O and blood. In the capillaries of each lamella, blood flows in direction opposite to the movement of water across the gill. Thus the most highly oxygenated blood is brought to water that is just entering the gills and has even high O2 content than the blood. As the H2O flows over the gills, gradually loosing its oxygen to the blood, it encounter the blood that is also increasingly low in oxygen. In this way a gradient is establishment which encourages the oxygen to move from water to blood


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IMPORTANCE: Counter current flow is very effective as it enables the fish to extract upto 80– 90% of the oxygen from water that flows over the gills. RESPIRATORY SYSTEM SYSTEM OF MAN MAIN FUNCTION OF RESPIRATION: The main function of respiratory system is inflow of O2 from the atmosphere to the body and removal of CO2 from body to the atmosphere. COMPONENTS OF RESPIRATORY SYSTEM: (1) PAIRED LUNGS The respiratory (gas exchange) organs. (2) AIR PASSAGE WAYS Which conduct the air (3) THORACIC CAVITY Which lodges the lungs (4) INTERCOSTAL MUSCLES AND DIAPHRAGM Which decreases and increase the diameters of thoracic c avity (5) RESPIRATORY CONTROL CENTRES Areas in brain which c ontrol the respiration. DETAILS OF COMPONENTS + THORACIC CAVITY: Paired lungs with in the pleural sacs are situated in the thoracic cavity. Separating the thoracic cavity from the abdominal cavity is a dome-shaped musculo-tendinuous partition called as Diaphragm. BOUNDARIES OF CAVITY: Thoracic cavity is supported by bony cage (thoracic cage) which is made up of Sternum -> in front Vertebral column -> at the back 12 pairs of ribs -> on each s ide Ribs are supported by Intercostal muscles FUNCTION: Increase in thoracic cavity diameter is responsible for inspiration. While decrease in diameter is responsible for expiration. AIR PASSAGE WAYS:


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Air is drawn into the lungs by inter-connected system of branching ducts called as “Respiratory tract” tract” or “Respiratory “Respiratory passage ways” Air passage ways consists of AIR CONDUCTING ZONE(which only conducts the air): 1. Nostrils 2. Nasal Cavity 3. Pharynx (nasopharynx and oropharynx) 4. Larynx 5. Trachea 6. Bronchi 7. Bronchioles (also called terminal Branchioles)

1. NASAL CAVITY: Atmospheric air enters the respiratory tract through a pair of openings called external nares (Nostrils), which lead separately into nasal cavity. Nasal cavity opens into naso pharynx through posterior nares (choanae). Nasal cavity is lined internally by Pseudostratified columnar ciliated epithelium containing mucous secreting cells. Hairs, sweat and sebaceous glands are also present. 2. PHARYNX: Air enters from Nasal cavity into pharynx through internal nostrils. The openings of nostrils are guarded by soft palate. It is internally lined by Pseudostratified ciliated epithelium, mucous glands are also present. 3. LARYNX (VOICE BOX): Pharynx leads air into larynx through an opening called glottis. Glottis is guarded by flap of tissue called epiglottis. During swallowing, soft palate and epiglottis close the nostrils opening and glottis respectively so that food is prevented to go either into nasal cavity or glottis. Larynx, a small chamber consists of pair of vocal cords. 4. TRACHEA (WIND PIPE): Larynx leads the air into a flexible air duct or trachea. It bears C-shaped tracheal cartilages which keep its lumen patent during inspiration. Its internal lining is pseudostratified columnar ciliated epithelium containing mucous secreting goblet cells. 5. BRONCHI: “At its lower end, trachea bifurcates into two smaller branches called Principle Bronchi↑ which leads the air into lung of its side. They are also supported by C shaped cartilage rings upto the point where they enter the lungs”.


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In all areas of trachea and bronchi, not occupied by cartilage plates, the walls are composed mainly of smooth muscles. 6. BRONCHIOLES: On entering the lungs, each bronchus divide repeatidly. As the bronchi become smaller, U-shaped bars of cartilage are replaced by irregular plates of cartilages. The smallest bronchi divide and give rise to Bronchioles (less than 1.5 mm in diameter). 7. TERMINAL BRONCHIOLES: Bronchioles divide and give rise to terminal bronchioles (less than 1 mm in diameter). Walls possess no cartilages and are almost entirely the smooth muscles. These are the smalled airways without alveoli.

DISORDERS OF RESPIRATORY TRACT: 1. LUNG CANCER (BRONCHIAL CARCINOMA): CAUSES: Smoking is a major risk factor either acitively or passively. Asbestos, nickel, radioactive gases are associated with increased risk of bronchial cascinoma PHYSIOLOGICAL EFFECTS: + LOSS OF CILIA: The toxic contents of smoke such as nicotine and SO2 cause the gradual loss of cilia of epithelical cells so that dust and germ are settled inside the lungs. + ABNORMAL GROWTH OF MUCOUS GLANDS: Tumor arises by uncontrolled and abnormal growth of bronchial epithelium mucous glands. The growth enlarges and some times obstruct a large bronchus. The tumours cells can spread to other structures causing cancer. SYMPTOMS: Cough- due to irritation Breath lessness – due to obstruction.

2. TUBERCLOSIS (KOCH’S DISEASE)(INFECTIOUS DISEASE OF LUNG): CAUSE: Caused by a Bacterium called as “MYCOBECTERIUM TUBERCLOSIS” PHYSIOLOGICAL EFFECTS: Tuber Bacili causes


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Invasion of infected region by macrophages Fibrosis of lungs thus reducing the total amount of functional lung tissues These effects cause Increased work during breathing Reduced vital and breathing capacity Difficulty in diffusion of air from alveolar air into blood. SYMPTOMS: Coughing (some time blood in sputum) Chest pair Shortness of breath Fever Sweating at night Weight loss Poor apetite PREVENTION: A live vaccine (BCG) provides protection against tuberclosis. 3.COPD-(CHRONIC OBSTRUCTIVE PULMONARY DISEASE): They include a. Emphysema b. Asthma a. EMPHYSEMA: CAUSES: It is a chronic infection caused by inhaling Smoke and other toxic substances such as Nitrogen dioxide and Sulphur dioxide PHYSIOLOGICAL EFFECTS: Long infection – Irritants deranges the normal protective mechanisms such as loss of cilia, excess mucus secretion causing obstruction of air ways Elasticity of lung is lost Residual volume increases while vital capacity decreases. Difficulty in expiration due to obstruction Entrapment of air in alveoli All these together cause the marked destruction of as much as 50-80% of alveolar walls. Loss of alveolar walls reduces the ability of lung to oxygenate the blood and remove the CO2 Oxygen supply to body tissues especially brain decreases. SYMPTOMS: Victim’s breathing becomes labored day by day. Patient becomes depressed, irritable and sluggish. Concentration of CO2 increases which may cause death.


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b. ASTHAMA: Respiratory tract disorder in which there are recurrent attacks of breathlessness, characteristically accompanied by wheezing when breathing out. CAUSES: It is usually caused by Allergic hypersensitivity to the plant pollens, dust, animal fur or smoke or in older person may be due to common cough. Heridity is major factor in development of Asthma. PHYSIOLOGICAL EFFECTS: Localized edema in walls of small bronchioles. Secretion of thick mucus. Spastic Contraction of bronchial smooth muscles (so the resistance in air flow increases). Residual volume of lung increases due to difficulty in expiration. Thoracic cavity becomes permanently enlarged. SYMPTOMS: The asthmatic patient usually can inspire quite adequately but has great difficulty in expiring.

HAEMOGLOBIN: “Haemoglobin is an iron containing respiratory pigment present in the red blood cells of vertebrates and responsible for their red colour.” STRUCTURE: Haemoglobin consists of 1. Heme 2. Protein (globin like chains) 1. HEME: One Haemoglobin molecule consists of 4 molecules of Heme. Each Heme molecule contains an iron (Fe++) binding pocket. Thus one molecule of Haemoglobin can combine with 4 iron atoms. 2. GLOBIN: Each Hb molecule contains four globin like chains (Two α chains and Two β chains). ROLE OF HB DURING RESPIRATION: Two major functions are performed by Hb. 1. Transport of O2 from lung to tissues.


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2. Transport of CO2 from tissues to lungs.

LUNGS: Lungs are paired, soft, spongy, elastic and highly vascularized structures, which occupy most of thoracic cavity. In child they are pink, but with age they become dark and mottled due to inhalation of dust. RIGHT LUNG: Partitioned into 3 lobes by two fissures. LEFT LUNG: Divided into 2 lobes by one fissures. PLEURAL MEMBRANES: Each lung is enclosed by two thin membranes called as Visceral and parietal pleural membranes. PLEURAL CAVITY: In between the membranes there is a narrow cavity, the pleural cavity filled with pleural fluid which acts as lubricant. FUNCTION OF CAVITY: 1. Cardinal function is to exchange gases. 2. Phagocytosis of air borne particles. 3. Temperature regulation. 4. Removal of water. 5. Maintainence of acid-base balance (by elemination of CO2). 6. Acts as Reservoir of blood.

LUNG CAPACITIES: 1. TOTAL AVERAGE LUNG CAPACITY: It is the maximum volume in which the lung can be expanded with greatest possible inspiratory efforts. VALUE: Total lung capacity = 5000 cm3 or 5 lit of air. 2. TIDAL VOLUME:


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The amount of air which a person takes in and gives out during normal breathing is called Tidal Volume. VALUE: 450cm3 to 500 cm3 (1/2 litre) 3. INSPIRATORY RESERVE VOLUME: '“Amount of air inspired with a maximum inspiratory effort in excess of tidal volume.” VALUE: 200 cm3 or 2 lit. (Average value) 4. EXPIRATORY RESERVE VOLUME: “Amount of air expelled by an active expiratory effort after passive expirations.” VALUE: 1000 cm3 or 1 litre. 5. VITAL CAPACITY: “After an extra deep breath, the maximum volume of air inspired and expired is called Vital capacity.” VALUE Averages about 4 litre. 6. RESIDUAL VOLUME: “Amount of air which remains in lung after maximum expiratory effort is called Residual volume.” VALUE: Approximately 1 litre or 1000 cm3. IMPORTANCE OF LUNG CAPACITY: Residual volume prevent the lung from collapsing completely. Responsible for gaseous exchange in between breathing. It is not stagnant since inspired air mixes with it each time. Aging or Emphysema, etc can increase the residual volume at the expense of vital capacity. MYOGLOBIN: Myoglobin is a heme protein, smaller than Hb, found in muscles and giving red colour to them.


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STRUCTURE: Myoglobin consists of one heme molecule and one globin chain. It can combine with one iron (Fe++) atom and can carry one molecule of O2.


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Chapter 14 TRANSPORTATION Diffusion: The movement of ions or molecules from the region of the higher concentration is known as diffusion. Examples: If a bottle of perfume is opened in a corner of a room, it can be smelt in the entire room. FACTORS ON WHICH RATE OF DIFFUSION DEPENDS: SIZE: Small molecules move faster as compared to the larger ones. Temperature: Rate of diffusion will be high at high temperature. CONCENTRATION GRADIENT: Greater the difference in concentration and shorter the distance between two regions, greater will be the rate of diffusion. FICILATATED DIFFUSION: The diffusion of the substance across the cell membrane through the specific carrier protein is known as facilitated diffusion. These membrane transport the protein are channel, proteins, receptors, cell pumps or carrier made up of usually proteins and don’t energy for transport. PASSIVE TRANSPORT: Movement of substances in and out of the cell, caused by simple kinetic motion of molecule, does not require the ATP is called as passive transport for example simple diffusion and facilitated diffusion. OSMOSIS: The movement of water molecules from the region of lower concentration through semi-permeable membrane, is known as osmosis. TYPES OF OSMOSIS: ENDOSMOSIS: The movement of water molecule into the cell when it is placed in hypotonic solution is called as endosmosis. EXOMOSIS: The movement of water molecule out of the cell when the cell is placed in a hypertonic solution is called as exosmosis.


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ACTIVE TRANSPORT: The movement of ions or molecules across the cell membrane against the concentration gradient from lower concentration to the higher concentration with the help of specific transport proteins in the cell membrane at the expense of cell’s metabolic energy ATP is called active transport. Examples Sodium potassium pump in nerve cells which pump Na+ out of the nerve cell and K+ into cell against the concentration gradient. IMBIBITION: Absorption of water and swelling up of hydrophilic (water loving substance) is called as imbibitions. HYDOPHILIC SUBSTANCES: Those which have great affinity for water are hydrophilic. For example starch, gum, cellulose, proteins seeds swell up when placed in water.   

Wrapping up of wooden framework during rainy seasons. Dead plant cells are hydrophilic The chemical potential of water is a quantitative.

WATER POTENTIAL: It is the difference between the free energy of water in pure water and energy of water in any other system or solution. Water potential is a relative quantity depends upon the gravity and pressure. USES OF WATER POTENTIAL: The direction of water flow across cell membrane can be determined. It is a measure of water status of plant. OSMOTIC POTENTIAL: The pressure exerted upon a solution keep it in equilibrium with pure water when the two are separated by the semi permeable membrane is called as osmotic pressure. It prevents the process of osmosis. OSMOTIC POTENTIAL: The tendency of the solution to diffuse it to another when two so lution of different concentration are separated by differentially permeable membrane is called as osmotic potential.     

It is represented by the beta for pure water beta = 0 The beta decreases as the osmotic concentration increases. It is the number of osmotic ally active particles per unit volume. Osmotic potential have been replaced by solute potential. The concentration of solute particles in a solution is called as potential beta.


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PLASMOLYSIS: If a cell is placed in hypertonic solution which have more negative solute and water potential than water will come out o f the cell by exosmosis and protoplasm start separating from cell wall leaving a gap between cell wall and cell membrane. This withdrawal of the protoplasm from cell wall is called as plasmolysis. The point where protoplasm just starts separating from cell wall is called as incipient plasmolysis. When it is completely separated, full plasmolysis occurs DEPLASMOLYSIS: When a cell is placed in a hypotonic solution or pure water, there will be an inflow of water by endosmosis. Protoplasm stars expanding and presses cell wall due to which pressure potential develops and water potential become less negative. This swelling of cell is called as deplasmolysis. WATER AND MINERALS UPTAKE BY ROOTS: 1. 2. 3. 4. 5. 6. 7.

Absorption of water and minerals salts takes place through root system. Roots are provided with enormous number of tiny roots hair. These roots hair a more in number in tap root system Root hairs are out growth of epidermal cells. Root hair increases the surface area for absorption. Most of the absorption takes place at root tips From hairs and epidermal cells water flow through cortex, endodermis, pericycle and then enter in xylem 8. There are three path ways for water to enter xylem. PATHWAYS TO ENTER THE XYLEM: CELLULAR PATHWAYS: In this route water flows through cell to cell the water enters into the root hair or epidermal cells down a concentration gradient. It flows through the cell wall and cell membrane and enter the adjacent cell from where water may again flow toward the deeper cells by osmosis. SYMPLAST PATHWAY: Cytoplasm of the cortical cells is interconnected by the small pores in the cell wall called as plasmodesmata. These pores provide another way of transporting the water and solutes across the plasma membrane at root hairs. APOPLAST PATHWAY: The cell wall of cortical or epidermal cell is hydrophilic and form a continuous matrix. Soil solution flows freely through these hydrophilic walls. The movement of soil solution through extra cellular pathway provided by continuous matrix os cell walls is known as apoplast pathway. TRANSPIRATION:


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The loss of water from the living tissues in the form of water vapours is called as transpiration. TYPES OF TRANPIRATION: CUTICULAR TRANSIPRATION: It is a thin layer present on the outer side of the epidermis. The loss of water through epidermal cells and their cuticle covering called cuticlar transpiration. LENTICULAR TRANSPIRATION: Lenticles are the areas on the outer surface of the body which are filled with loosely arranged cells called complimentary cells. STOMATAL TRANSPIRATION: In the epidermis of the leaf small pores are present called stomata. MECHANISM OF TRANSPIRATION: The transpiration is an evaporation process. Most of the transpiration occur in two stages. 1. Evaporation of water from mesophyll cell walls into intercellular spaces. 2. And then diffusion into the outer atmosphere. Relatively humidity plays a very important role in the mechanism of transpiration. Loss of water depends upon the relative humidity of atmosphere. Higher the relative humidity, lesser is the loss of water The atmosphere is rarely saturated with water vapors. The water vapors present in dry air of the atmosphere have some diffusion pressure. Drier the air, lesser is the vapor pressure of water vapors. The air present in the intercellular spaces of mesophyll cells is saturated with water vapor as it is in contact with the cells of mesophyll and therefore this air in the intercellular spaces has high vapour pressure. Due to the difference in the vapor pressures between outer atmosphere and inside the leaf leaf water vapor diffuse out through stomata from their high vapor pressure to lower vapor pressure. Thus transpiration is essentially a simple diffusion process which is how ever controlled by the movement of guard cells of stomata. STRUCTURE OF STOMATA: The stomata are minute pores in the epidermis of a leaf. It has two kidney shaped cells called guard cells. The o pening and closing of the s tomata depends upon the changes in the turgidity of their guard cells. When the guard cells are flaccid stomata are closed. When the turgidity increases the outer thin walls of the guard cells stretch outward. These walls also stretch the inner walls outward. The inner wall is inelastic, there fore it becomes con cave. As a result the space between the guard cells widens and stomata open. FACTORS INFLUENCE THE OPENING AND CLOSING OF THE STOMATA: There the two factors that influence the opening and closing the stomata. 1. LIGHT:


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Light plays an important role in the opening and closing of the stomata. The stomata open in light and close in the night. The guard cells contain chlorophyll, they manufacture carbohydrates during sunlight. By the formation of the sugar the osmotic pressure of guard cells increases, so water enters the guard cells due to endosmosis from the neighboring cells of epidermis. It increases the turgidity of guard cells which open stomata. In the darkness Carbohydrates are consumed in the guard cells or these are transferred into other cells. It decreases the osmotic pressure of the guard cells, due to this process exosmosis takes place, guard cells become flaccid and stomata are closed. 2. CONCENTRATION OF K+ ION: In some plants the turgidity of guard cells is regulated by K+ ion concentration. During day time the guard cells get K+ ion from neighboring cells, due to their accumulation osmotic potential of guard cells is lowered and they get water from epidermal cells, So the guard cells become the turgid and stomata are opened. Less concentration of K+ ions result in the closing of the stomata. DIFFERENCE BETWEEN THE CIRCULATORY SYSTEM OF COCKROACH AND EARTHWORM: Cockroach It has open type of circulatory system. The blood flows through the body sinuses The blood directly comes in contact with body tissues. The true body cavity coelom is reduced. Blood are interstitial fluid are not separated Distribution of blood is poorly controlled

Earthworm It has closed type of circulatory system The blood flows through blood vessels. The blood does not come in contact with the body tissues. Coelom is large Blood is separated from the interstitial fluid of cells Distribution of the blood is properly controlled.

SINGLE CIRCUIT PLAN: In the fishes the heart works as a single works as a single circuit heart. That means that the blood flows in one direction only. The heart of fish consist of the two chambers one atrium and the o ther one is ventricle. The atrium received the deoxygenated blood from the body through the sinus venous. The atrium open into ventricle, which has thick muscular wall. By the c ontraction of the ventricle the blood is transferred into the ventral aorta through conus arteriosus. From ventral aorta the blood is carried to the gills for oxygenation. The heart of fishes does not receive the oxygenated blood, so the gills receives the oxygen and then it is supplied to the body. From the body deoxygenated blood is carried to the heart. In this way the blood flows in one direction only, it is called single circuit plan. DOUBLE CIRCUIT PLAN: In amphibians, reptiles birds and mammals double circuit plan is present. Because heart receives oxygenated blood from lungs and it is supplied to different parts of the body. It is called as systematic system. BLOOD:


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Blood is red color fluid found in the body of man and other naimsl. It is a connective tissue and composed of two constituents. PLASMA: It is the liquid part of the blood and form 55% of the blood. It is non living part and it is 90% part is composed of water in which a large number of inorganic and organic substances are dissolved such as inorganic salts, blood proteins, glucose, amino acids, triglycerides, urea, harmones, enzyme and autotoxins. BLOOD CORPUSCLES: The blood corpuscles make up the 40% of the blood. These corpuscles are of two types. (i)

RED BLOOD CORPUSCLES:

These corpuscles are also called erythrocytes. They are circular, oval shaped, biconcave and without nucleus. They are prepared in bone marrow but due to the phagocytes of spleen they are destroyed after 120 days. The iron is retained in the body and returned to the bone marrow. The remaining portion is passed out. (ii)

WHITE BLOOD CORPUSCLES:

They are termed as leucocucies. They are color less without any regular shape and contain nucleus. Majority of them are larger than red blood corpuscles. But they are less in number. TYPES OF MYCELIUM: PRIMARY MYCELIUM: In besidiomycta is formed by the germination of beasidiospore, which is haploid and monokaryotic i.e. uninucleate. SECONDARY MYCELIUM: It is diakaryotic i.e. binucleate formed primary mycelium as a result of plasmogamy which bring the two haploid nuclei close together in the same cell. This binucleate cellfrom secondary mycelium by division. TERTIARY MYCELIUM: it is formed from secondary mycelium as a result of plasmogamy karyogamy and development of s pecialized tissue called sporophores or fruiting bodies. There sporophores produced spores by meiosis. HYPHAE: Hyphae are long slender, branched or un-branch tubular thread like structures which make the body of fungus called Mycelium. Septum is cross wall which prevent the follow and distribution of material between individual cells of hyphae inseptate hyphae incomplete septa acts as pores between two cells which help in the flow of material and cytoplasm between cells of hyphae, it help in the growth of hyphae. FUNGUS:


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A eukaryote heterotrophy the body of which is either multicultural threat like hyphae or is unicellular and no hyphae or thread like structure are formed. The cell wall is present and made of chitin MYCORRHIZAE: Mycorrhizae are symbolic association of fungi with roots of higher plants. In this association both partners get benefit. The fungus increases the absorbing get benefit. The fungus increases the observing surface of higher plant helping the plant to absorb nutrients from the soul. While shelter is provided to the fungus by the roots of higher plant.


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Class XI Biology Notes first year sindh board

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