CHARACTERISTICS CHARACTERISTICS OF LIVING THINGS. All living things are made up of tiny units called cells and perform three vital functions. Cell structure. A cell is the smallest living unit that makes up a living thing. Plant and animal cells have the following parts:
The nucleus controls the functions of the cell, such as reproduction. The cell membrane controls what enters and leaves the cell. The cytoplasm is a jelly-like substance in the cell where chemical reactions happen. The vacuoles contain water and minerals, which the organism needs in order to grow.
In addition to the t he above characteristics, characteristics, plant cells have:
A strong wall, which protects the cell and gives it its shape. Chloroplasts, Chloroplasts, which contain chlorophyll needed during photosynthesis.
Some organisms, such as Pamecium, have only one cell. These are called unicellular organisms. In a unicellular organism, the single cell performs performs all three vital functions. Other organisms, such as birds, are made up of many cells. They are called multicellular organisms. In a multicellular organism, the different cells carry out different functions.
Vital functions. In spite of their differences, all living things perform three vital functions: nutrition, reproduction and interaction. These processes, however, are carried out in different ways according to the organism. Nutrition: All living things obtain nutrients from their environment and transform them into energy. This energy allows them to live, grow and develop. Different organisms get their energy via different processes:
Plants produce their own food through photosynthesis. Animals can’t produce their own food, so they feed on other l iving things. Decomposers, such as fungi and bacteria, feed on the remains of dead plants and animals.
Reproduction: This process allows living things to produce new organisms similar to them. Reproduction can be sexual or asexual.
Asexual reproduction occurs when only one organism is required, as is the case of bacteria.
In sexual reproduction, two different types of individuals are required: male and female.
Interaction: All living things interact with their environment. A change in the environment can cause a reaction. We call this change a stimulus, and the reaction, a response. Animals use their sense organs to detect some stimuli. Most plants have no sense organs but they react to stimuli too.
