SPM PAPER 3 (mainly applicable to Biology and Chemistry) SPM Biology Paper 3 (applicable to Paper 3 Chemistry but not so for Physics P3 Guidelines on how to answer Paper 3 questions. he following pointers were made a!ailable by M"# to schools as SPM e$amination techniques for answering Biology Paper 3 questions. a%e a%e note that it i t is relati!ely easy to score high mar%s in Paper 3 if you are able to follow the suggested answering techniques closely. PAPER 3 : QUESTION 1 The following scientific skills are tested in Qestion 1: 1! O"SER#ATION &'#S") * State two obser!ations+. ,)S-# * -rite down what can $e o$ser%ed onl& . /o not do any analysis0 comparison or conclusion. 1or most e$periments0 the obser!ation can be written in the form* he +.(responding !ariable2 +.. at +..(manipulated !ariable2+ is (state reading of measuring instrument2 ( Write the observation for the highest and lowest value of the responding variable.) '! IN(EREN)E State one inference which corres*onds to each o$ser%ation . ,n inference is a brief e$planation of the obser!ation0 based on scientific %nowledge which you already %now. (But in Physics0 the scheme demands that inferences be written as follows* he (responding !ariable2 is determined byaffected by influenced by controlled by changed by (manipulati!e !ariable2. 3! +EASURIN, AN- USIN, NU+"ERS Record the reading of thermometer0 stopwatch0 measuring tools 0 ruler etc. from the gi!en diagram. Be careful of the number of decimal places which you should ha!e in your readings. .! )O++UNI)ATIN, Construct the table using the gi!en titles0 record the rele!ant data or calculation. 'nits of measurements should be written together with table titles0 not with readings. /! INTERPRETIN, -ATA #$plain state the relationship between manipulated and responding !ariables as obtained from a graph of the results. 0! )ONTROIN, #ARIA"ES #aria$les +ethod to handle the %aria$les 2STATE 2+UST USE #ER" and state the INSTRU+ENT sed M,)P'4,#/ 'se +. #SP")/)G ecord measure using +. ("bser!e read are not accepted2
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'se the same+ Maintain +
4! +A5IN, 67P6OT6ESIS ,ble to state the hypothesis correctly based on the following criteria* State the manipulated !ariable
State the responding !ariable elate the manipulated !ariable and the responding !ariable (-hen relating m! and r!0 do not use neutral relationships li%e 5affects6 or 5influence6 or 5changes with6. Commit yourself to one of the following relationship terms* 5increases with6 5decreases with6 . 8! PRE-I)TIN, &'#S") * f the e$periment is repeated +..0 predict the obser!ation ++ ,)S-# * "ne number or rele!ant statement e.g. the (responding !ariable2 will be higher lower than (the !alue in the first e$periment2 9! -E(ININ, OPERATIONA7 his is a definition in the conte$t of the e$periment0 and not the te$tboo% definition. #7,MP4# 8* ,n e$periment is carried out to in!estigate photosynthesis and the number of bubbles released is counted. he operational definition of photosynthesis would then be* Photosynthesis is the process where green plants release bubbles in the presence of light0 carbon dio$ide and water. #7,MP4# 9* ,n e$periment is carried out to in!estigate photosynthesis and lea!es are tested with iodine solution for the presence of starch. he operational definition of photosynthesis would be* Photosynthesis is the process where green lea!es in the presence of light0 carbon dio$ide and water0 produce starch which turns iodine solution dar% blue. (You must have a phrase which includes the context of the experiment / experimental conditions.)
Or even simpler: To define operationall! sa the "uestion is as#ing ou concerning Operational $efinition of %trong &cids! and the manipulative variable is the acid with various p' value and the responding variable is The eading of The p' meter. 'ence the operational definition is : & strong acid causes the p' meter to show a smaller magnitude reading when the bulb of the p' meter is immersed in each of the samples of various concentrations of the acid! given that the volume of the tested acids is the same and all acids are of the same tpe. (Note: The operational definition is supposed to tell a person (whom you assume does not know a single thing about the chemical principles in the first place) what to observe as the responding variable and the conditions in which the experiment is taking place (tell what is the fixed variable and the how the manipulated variable is represented) Another example is: The elasticity of vulcanised rubber Given the experiment is the experiment comparing the elasticity of two strips of rubber
one vulcanised the other non!vulcanised" #ence the operational definition of $the %lasticity of &ubber$ is given as: The %lasticity of &ubber is operationally defined as the 'ifference between final lengths of the respective rubber strips after the weight used to stretch is removed and their respective original lengths' given that the two rubber strips have the same initial length but are of different types of rubber one being vulvanised rubber the other being non! vulcanised rubber" Another example: define operationally the &ate of &eaction (based on the experiment on this actor: Temperature of reaction mixture) i"e" the effect of temperature on the rate of reaction between *odium Thiosulphate solution and dilute sulphuric acid #+*,hence we define the $&ate of &eaction$ as follows: The rate of reaction is operationally defined as 'The time taken for the cross $.$ to disappear' when the 'sodium thiosulphate solution is heated to various temperatures' and then reacted with dilute sulphuric acid given that both the 'dilute sulphuric acid and sodium thiosulphate solutions are of standard volumes and concentrations'" Note that / have inverted comma!ed the $responding variable!!!the factor we are supposed to observe$ the $manipulative variable!!!the variable being obviously manipulated here$ and also the $fixed variable!!!the variable being clearly controlled here$"
1! )ASSI(7IN, Students must complete the gi!en table according to the title . f the table is not pro!ided0 construct the table according to the classification gi!en . 11! USIN, SPA)E;TI+E REATIONS6IP State the changes of the responding !ariable with time. 'se relationship words li%e increases with decreases with remains constant with increases proportionately with etc. /o not use neutral relationship terms li%e affects influences changes with. PAPER 3 : QUESTION ' This <estion tests stdents a$ilit& to *lan an e=*eri>ent in a gi%en for>at! Stdents >st ha%e all of the following : 8. Problem statement
9.
,im of in!estigation
3.
:ypothesis
;.
=.
4ist of apparatus and materials
>.
echnique used
?.
#$perimental procedure or method
@.
Presentation of data
A.
Conclusion
1! PRO"E+ STATE+ENT Must be written in the form of a <estion remember to end with a question mar%.
'! AI+ -rite down the aim as gi%en in the question.
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3! 67POT6ESIS ,ble to state the hypothesis correctly based on the following criteria* State the manipulated !ariable
State the responding !ariable Relate the manipulated !ariable and the responding !ariable (emember no neutral relationship terms2
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.! #ARIA"ES -rite down all 3 !ariables (one of each2 /! TE)6NIQUE n a complete sentence0 write down what is o$ser%ed or >easred (include the instrument used2. State the specific name of the technique where applicable. #$ample * (i2 Measure and record the !olume of fruit uices needed to change blue /CPP to colourless0 using a syringe. (ii2Measure and record the initial and final temperature of the water in the boiling tube using a thermometer. 0! +ATERIAS AN- APPARATUS 4ist down at least 3 materials and 3 apparatus . 4! PRO)E-URE ? +ET6O-rite down each ste* clearly and systematically (inclde *recationar& ste*s 2 . Dour steps should include the following* E8 Steps where you describe how apparatus and materials are handled. E9 Steps where you describe how the controlled !ariable is maintained E3 Steps where you describe how the manipulated !ariable is altered E; Steps where you describe how the responding !ariable is measured and the instrument to be used. E= Precautionary steps which ensure safety impro!e accuracy of readings. (%ince this is a planning of an experiment to be carried out! procedures should be written as a set of instructions and not in passive speech. 8! PRESENTATION O( -ATA Construct the ta$le with the correct titles and nits (able is to be left blan%0 without results readings2. 9! )ON)USION epeat or modify the hypothesis sentence. t is not required to write the phrase Ftherefore the hypothesis is accepted reected (since you are planning an e$periment and ha!e not carried it out.2
