PAPER ONE

No Answer26 C27 B28 C29 B30 D3l A32 DaaJJ C34 D35 A36 A37 C38 C39 B40 D4I C42 A43 B44 A45 A46 D47 C48 A49 C50 C

No AnswerI D2 BaJ A4 C) B6 A7 B8 D9 A10 A1l AL2 AI3 BT4 A15 DI6 C17 D18 Bt9 B20 A2l B22 B23 A24 D25 C

PAPER TWO

SECTION A

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MARKS:,.....ii lii 'i,.l.lit,,,.2 (a) X = Interphase

Y = M phase/mitotic phase

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(b) Pl : P is growth phase 1 /Gl

P2 : Protein / new (cytoplamic) organelles aresynthesized

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(c) To reproduce asexually I I

(d) Prophase, Metaphase, Anaphase, Telophase 1 1 All 4 must becorrect sequences

(e)(i) Pl : Vesicles formed at the centre of the cell

P2 : The vesicles fuse to form a cell plate

P3 : The cell plate fuse to form new cell wall and plasmamembrane

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I 2 Any 2

(e)(ii) Stage T in plant cell formed a cell plate but the animalcell formed a cleavage furrow during stage T ll cleavagefunow pinches inward whereas cell plate grow outward

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(f) P1

P2

P3

Too much exposure to ultraviolet rays in the sunlightll Too much exposure to carcinogenic substances

Causes lLead to uncontrolled mitosis

The person will get cancer /tumour

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3(a) (i) P: Liver

Q = Pancreas

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I 2(a) (iD P1

P2

P/ Liver produces bile

To emulsifu fatllipid into tiny droplets

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1 2(b)

Class offood

Enzyme Productsof enzymedigestion

Starch Amylase Maltose

Protein Pepsin Polypeptides

Lipids Lipase Fatty acids andglyserol

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(c) F1 : The small intestine has numerous villi / microvilli//Small intestine is longEl : To increase surface area for absorption of

nutrients / digested food

F2 : The wall of the small intestine is covered withepithelial cells which are one cell thick

E2 : The absorption of nutrients / digested food will befaster /easier

F3 : Large network of blood capillary inside thevilus/lactealE3 : To transport more nutrients/digested food

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FandE=lM

(d) P1. JogginglExercise/ Aerobic/ Any physical activities

P2. Reduces food rich in fat/Eg.

P3. Reduces food rich in sugar/carbohidrate

P 4. Eat more fruiVveeetables

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a(a) (i) X: Menstruation 1 I Reject:Menstrual cycle

(a) (ii) The thickness of endometrium tissue is decreasins I I

(bxi)

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g First zgr month Il*

Second 28month I

Thirdmonth

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(bxii) Pl: Corpus leteum does not disintergrateP2:Corpus luteum continue to secrete progesteroneP3: The thickness of the endometrium tissue is maintain

II1 2 Any 2

(cXi) Parent

Parentsomatic cell

Mrs A/ Female

(44 +XX) x

, / \

Mr A/ Male

(44 + XY)

/ \

Gamete: (22+X) (22+X)

Offspring (44 +XX)Genotype

Offspring FemalePhenotype

(44 +XY) (44 +XX) (44 +XY)

Male Female Male

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(c) For organisms to adapt to the sunounding l/

For survival of the organisms //

To camouflage from predators//

One individual to be distinzuished from others 1 Any I(d) Continuous

variationDiscontinuousvariation

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PI It exhibitsphenotypeswith intermediatecharacteristics

It exhibits a fewdistinct phenotypes /with no intermediatecharacteristics

P2 The phenotype isinfluenced by theenvironment/nutrition /exercise

The phenotype is notinfluenced by theenvironment/nutrition / exercise

P3 It is controlled bytwo or more genes/many pairsof alleles

It is controlled by onegene/ a pair of alleles.

P4 The( frequency)graphshows a normaldistribution

The( frequency) graphshows a discretedistribution

(eXi) Pl : Individual P has 3 chromosome at chromosomenumber 21 but Individual Q has 2 chromosomes atchromosome number 21

P2 : Individual P has sex chromosome X and Y butIndividual Q has two X chromosome.

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(e)(ii) Pl : During meiosis, the homologous chromosomenumber 21 failed to segregate

P2 : Produce gamete withz4 chromosome

P3: The abnormal gamet fuse with the normal gamet toproduce a Down 's syndrome offspring/extra one21 chromosome

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SECTION B

Able to explain how during vigorous activity the bodyregulates the content of carbon dioxide in the blood

Pl- During vigorous activity, the concentration / thepartial pressure ofcarbon dioxide increases as aresult of active cellular respiration

P2- the carbon dioxide react with water to formcarbonic acid

P3- which results in a drop in the pH level of the blood(and tissue fluid that bathing the brain)

P4- The drop in pH is detected by the (central)chemoreceptors in the medulla oblongata

P5- and detected by peripheral chemoreceptors// carotid bodies and aortic bodies

P6-The central chemoreceptors and pheripheralreceptors send nerve impulses to the respiratorycentre in the medulla oblongata

P7- The respiratory centre sends nerve impulses to thediaphragm and the intercostal muscles,

P8 -causing the respiratory muscles to contract and relaxfaster

P9- As a result, the breathing and ventilation rateincrease the oxygen concentration retum to thenormal level

P10- Thus excess carbon dioxide is eliminated fromthe body, the oxygen concentration return to thenormal level, /the carbon dioxide concentration /pH value of the blood return to normal level

Students are able to explain why the pulse rate takesseveral minute to return normal

Pl- During the activity the oxygen intake is not able tomeet the oxygen demand of the body.

P2- Respiration has to take place anaerobically// anaercbic respiration occur

P3- As a result, lactic acid accumulates in the muscle.

P4- The pulse rate is high for several minutes to supplyoxygen to oxidize lactic acid

P5 - Once all the lactic is oxidized, the pulse rate returns tonormal

Students are able to explain the aerobic and anaerobicrespiration

F1-Anaerobic respiration process occur in paddy seedlings

P 1 -involves the break down of glucose in the absence ofOxygen / in a limited supply of oxygen to releaseenergy

P2 -Oxidation of glucose is incomplete /2 molecules of ATP are produced

P3 -The by-products are ethanol , energy and carbondioxide

F2-Teresterial Plant carries out aerobicrespiration aerobically in diagram 6.3a

P4- Aerobic respiration process involves the (complete)oxidation of glucose in the presence of oxygen torelease energy

P5- In a waterlogged condition // less amount ofdissolve oxygen is available

P6- The roots of terrestrial plants respire anaerobically

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P7-Terrestrial plants are unable to carry out anaerobicrespiration for a long term

P8 -causing the plants to wilt/ die

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rrllI4ARS-Slrlr.

7(a)Blood circulatory

systemLymphatic system

I Capillaries are notblind-ended.

Lymph capillaries areblind ended.

2 Arteries do not havevalves ( but veinshave valves.)

All lymph vessels havevalves.

3 No (lymph) nodespresent.

Lymph nodes present.

4 Direction of flow isboth towards the heartand away from theheart.

Direction of flow isalways towards the heart.

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Do notacceptanswers thatdescribesdifferences inblood andlymphcontents

(b) o P:Sinoartr ialnode. Q: Atrioventricular nodeo R: Bundle of His fibreso S: Purkinje fibres

{{./ 2

4.,1:2 marks24^l:l mark1{:0 marks

F1 : P generates electrical impulses which spread rapidlyover the walls of both atrium causing both atrium tocontract

F2: From P/ SA node, the impuls reaches Q /atrioventricular node (AV node)

F3: From Q, impuls is conducted through R / bundle ofHis fibres and to the apex of the heart

F4: Impulses move along the walls of the ventriclesthrough the Purkinje fibre causing the ventricles tocontract.

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Explanation:Fl : R has (no Hepatitis A antigen and) no antibodies

against Hepatitis A

Max5

Explanation

5 marks

Discussion5 marks

El : R is not infected by the virus / has never got infected

F2 : S has (no Hepatitis A antigen but has) antibodiesagainst Hepatitis A.

E2 : S had been infected with undergone the disease andrecovered / S has

been vaccinated against Hepatitis AE3 : Therefore, S's immune system has produced

antibodies against the disease

F1

E1

E2

F2

F3

E3

S's level of antibody against Hepatitis A in the bloodis above the immunit)' level

S need not be immunised because he has acquirednatural active immunity / artificial active immunitli

Thus, S has immunity against future Hepatitis Ainfections

R does not have any antibody, so need to beimmunised against the disease by vaccination.

The vaccine stimulates the immune system of R toproduce antibodies against the Hepatitis A virus.

R acquires artificial active immunity against Hepatitis

Pl - receptor is stimulated by the stimulus / thedog and generates impulse

P2 -impulse is transmitted ( along dendrites tocell body ) /P/Afferent neurone / sensoryneurone

L2

P3 - (the impulse is ) transmitted to theInterneurone / Q in the spinal cord

P4 -The impulse is then transmitted to R/efferent neurone / motor neurone

P5 -R transmits the impulse to the effector /muscles

P6 - impulse is generated in the muscle fibre,/effector causing it to contract

P7 - Allow the man to run I fightthe dog

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Role of endocrine system and nervous system inregulation of body temperature:

Role of endocrine system:

P1-When the body temperature increase / higherthan normal / 37C

P2 -Thyroid gland /Adrenal gland secretes lessthyroxine / adrenaline ( hormone)

P3 - Decreases the metabolic rate ,( Lessgeneration of heat in the body /

P4 - decrease the body temperature back tonormal

OR

P1-When the body temperature decrease / belowNormal/37C

P2 - Thyroid gland /Adrenal gland secretes morethyroxine / adrenaline ( hormone)

P3 - increases the metabolic rate , (thus increasesthe generation of heat in the body)

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P4 -thus increases the body temperature back tonormal3T C

Role of nervous system :

Pl -When the surrounding temperature increase ,change of the surrounding temperature is

detected by (thermal) receptors (in the skin)

P2 - The receptor produces impulse

P3 - the impulse is then sent to hypothalamuswhich initiates the negative feedbackmechanism

P4 - that will bring about : sweating,P5 - vasodilationP6 - lowering of skin hairs

OR

Pl -When the temperature surrounding decrease ,change of the surrounding temperature isdetected by (thermal) receptors (in the skin)

P2 - The receptor produces impulse

P3 - the impulse is then sent to hypothalamuswhich initiates the negative feedbackmechanism

P4 - that will bring about : shiveringP5 - vasoconstrictionP6 - erecting the skin hairs

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II1 Max 6

8 c Pl - Broken families I family problemsNo support from families member when thevhave problems

P2 - Influence of friend s / peer pressurePersuasion from friends to take drugs to beaccepted by

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P3 - Out of curiosity to tryWanting to try and feel how it taste and itseffect

P4 -Lack of knowledge to the dangers of thedrugsLack of information from families/ friends/adults

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Fl -Airpollut ion

Pl - exhaust fumes from vehicles contain soot / leadlcarbon monoxide/ oxides of nitrogen/ hydrocarbons

P2 - Burning of fossil fuels in the combustion engine thefactories release large amount of carbon dioxide intothe atmosphere

F2 - Noise pollution

P3 - Caused by machine for logging activities /noise frommoving vehicles

F3 - Thermal pollution

P4 - Glass buildings trap heat forming heat islands /increase in surrounding temperatureP5- Hot water discharge from the factories into the river

nearby

F4 -Water pollution

P6- Caused by factory waste such as heavy metal lleadlmercury

P7 - Logging activities cause the soil to loosen and flowinto the river

P8 - Soil /sediments are deposited in the river Any 10

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F4: Preservation and conservationE4 : protect forests/ swamps//reduce deforestation.

(There is more fresh air because of existence of trees)

F5: Plant more treesE5: to absorb more carbon dioxide

F6 : Altemative waste disposalE6 : Avoid open buming/ Use incinerators I bury

biodegradeable waste

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Choose any 3pairs ofF+E

max 6

TOTAL20

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PAPER 3

Question I

1 (a) K80603 - Measurin and usin number

All data is correct.

Concentration ofsalt solution P/o\

Volume ofurineproduced (ml)

0.1 36.4

0.5 25.6

1.0 20.0

1.5 16.6

No respons el I wrong response

Able to state any two observations correctly //Fulfill all criteria :

When the student drinks 0.1% salt solution, thevolume of urine produced is 36.4 ml.When the student drinks 0.5% salt solution, thevolume of urine produced is 25.6 ml.When the student drinks 1.0% salt solution, thevolume of urine produced is 20m1.When the student drinks 1.5% of salt solution,the volume of urine produced is 16.6 ml.When the student drinks 0.1% salt solution, thevolume of urine produced is the most.When the student drinks 1.5% of salt solution,the volume of urine produced is the least.

Accept:Any suitable answer

o Concentration ofsalt solution (mv)

o Volume of urineproduced (rv)

r Value of mv andrV

2 Able to state any one observation correctly // stateany fwo obseruations but inaccurate,1. When the student drinks O.lYo salt solution, the

volume of urine produced is more.2. When the student drinks l.5o/o of salt solution. the

volume of urine produced is less

Any two criteria only

I Able to state ideas of observation1. The volume of urine produced depends on / is

influenced by the concentration of salt solution2. Different concentration of salt solution produce

different volume of urine

Only one criteia Iidea onlv

0 No response / wrong response

ii) K80604 - Making inference: : r ' : : l _r j ._. r ' , . .

aJ Able to state any two inferences correctly.

For observation I,2, 5.Less salt in the blood/ blood osmotic pressure decreases, thus

water reabsorbed at the kidney (tubule) is less.

For observation3,4,6.More salt in the blood/ blood osmotic pressure increases, thuswater is reabsorbed at the kidney (tubule) is more

2 Able to state any one inference correctly // state any twoinferences but inaccurate.

1. At low concentration of salt solution, the student producesthe most urine because less water is reabsorbed (into theblood capillary in the kidney)

2. At high concentration of salt solution, student produces theleast urine because more water is reabsorbed (into bloodcapillary in the kidney)

Able to state idea of inference.

0 No response / wrong response// only one idea

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K80610 - Controllin variables

KB0611 - Statin the h

- verb

-mv

- verb

-ry

- appuatuS

- verb(fix)-cv- value

Manipulatedvariable:Concentration of saltsolution

Method of changing the maniputat"avariable:Use different concentration of saltsolution of 0.I% ,0.5oh, I.0o/o, and I.5%

Respondingvariable:Volume of urineproduced

Determine what to observe in ttreresponding variable:Measure and record the volume of urineproduced by using a measuring cylinder

Constant variableVolume of saltsolution drunk

Method to fix the constant variabl,e:Fix/Maintain the volume of salt solutiondrunk at 250m1

//wrong response ll only one cor..,ct

Able to state the hypothesis.o.."ffil. The higher the concentration of salt solution, the lower the

volume of urine produced.2. When the concentration of salt solution increases. the

volume of urine produced decreases

Criteriaorv

.mv

r relationshipbetween mvand rv

Able to state the hypothesis inaccfficoncentration of salt solution, increases/decreases volume of urine

rv has no value

Able to state the idea of trypotn1. If the concentration of salt solution is different, the volumeof urine produced is different2. The concentration of salt solution affect/depend the volume

of urine produced

/ wron

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l fe) fi) TableScore

aJ

Able to construct a table and record the result of the experiment with the

following criteria:

Kl - state all titles with units correctlyK2 - transfer all data correctlYK3 - correct calculation

Concentration of saltsolution (%")

Volume of urinenroduced (ml)

Percentage of urineoroduced (%o)

0.1 36.4 14.6

0.5 25.6 10.21.0 20.0 8.01.5 16.6 6.6

2 Able to construct a table and record any two criteria

I Able to construct a table and record any one criteria

0 No response / wrong response

KB0606 - Communications

The graph isdrawn accordingto students'results in e(i),even if the answerin e( i )is wrong

Bar chart : refer to page 18Able to draw a graph according to all3 criteria.Criteria:

o P - axis with the correct unitso T-correctdatao G - smooth graph / free hand drawing

Able to draw a graph based on two criteria'

Able to draw a graph based on one criteria.

No response / wrong response

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I KB0608 - In n of data

aJ

Able to explain the relationship between the concentration ofsalt solution drunk and the percentage of urine produced

o The higher the concentration of salt solution drunk. the lowerthe percentage of urine produced

o The blood osmotic pressure increase. causing more water to be reabsorbed at the kidney (tubule)

(Accept any other correct relationships)

Criteriao Relate the

concentrationof salt solutiondrank with thevolume ofurine produced

o Explanationusing

-blood osmoticpressure

- waterreabsorbed intocollectingtubule ofkidney / bloodcapillary

2 Able to interpret data accurately but with no explanation

I Able to state the idea0 No response / wrong response

K80609 - definition

J

Able to state the operational definition correctly.

Osmoregulation is a process the process of maintaining thewater content of the blood / the blood osmotic pressure of thestudent shown in this experiment as the volume of urineproduced when salt solution of different concentrations is drunk.

o Measurable rv.mv

2 Able to state operational definition inaccurately.

Osmoregulation is a process that produces different volume ofurine

No mv

I Able to state the idea.

Osmoregulation is a process that produces urineTheory

0 No response l/ wrongresponse

2l

K80609 - Prediction

aJ

Able to predict correctly with explanation.

o volume of urine produced is more than 36.4 mlo blood osmotic pressure decreases. causing less water to be reabsorbed at the kidney

Prediction withvalue (1 mark)

Explanation (2marks)

2 Able to state any two criteria correctly. \-o value inwediction

I Able to state the idea Prediction only

0 No response / wrong response

KB0602- ClassificationRemarks i .

Able to classify all materials and apparatus correctly.

MaterialsBahan

ApparatusRadas

BeakerMeasuring cylinder

StopwatchDrinkins cup

Distilled waterSalt solution

6 { :3m4-5.,1 :2m1-3{=1m

0 No response ll wrongresponse

0)C)

tsrao)-L,^=s

H.v

obo

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(l)okC)

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The percentage of urine produced against theconcentration of salt solution drunk bv the student

Concentration of salt solutiondrunk by the student (%)

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Question 2:Problem Statement

Able to state the problem statement correctly with ail criteria:

. Manipulated variable - pH (of the medium)

. Respondingvariable -population growth / number of Lemna sp.' Relationship in question form with question symbol [?]

Sample answers:1. Does pH affect the population growth / number of Lemna

sp.?2. What is the effect of pH on the population growth / number

of Lemna spJ

Criteria-Mv-Rv- Relationshipin questionform withquestionmarks

Able to state the problem statement with two criteria.

Able to state the problem statement with one criteria or ideaNo

sH

aJ Able to state the hypothesis correctly according to the criteria

' Manipulated variabler Responding variabler Relationship between mv and rv

Sample answers:1. pH 7/ neutral medium is the most suitable for the population

growth/ number of Lemnq sp. compared to pH Slacidjc mediumand pH 9lalkaline medium.

2.The population growth / number of Lemna sp. is the highest inpH7lneutral medium compared to pH Slacidic medium and pH9 /alkaline medium.

3. pH7 / neutral medium most suitable for the population growth/number of Lemna sp.

Criteria-Mv-Rv- Relationship

of mv and rv

2 Able to state the hypothesis with two criteriaSample answers:L pH is suitable for the increase in population / growth / number

of Lemna sp.2. Neutral medium / pH 7 is most suitable for the population /

number of Lemna sp.

1. No valuefor mv2. No value ofrv

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I Able to state the idea of the hypothesis.Sample answers:1. pH affects the population of Lemna sp.2. Population of Lemna sp. depend on pH

No value for mvor rv

0 No response / wrong response

Variables:

Able to state the three variables correctlv

Sample answers:Manipulated variable: pH (of medium) llpH 5, pH 7 andpHg//acidic medium,

neutral medium and alkaline mediumResponding variable : The population growth / number of Lemnasp.Constant variable : Plant species // volume of medium used /

concentration of nutrients / temperature /light

intensity / time for counting the population/ number of Lemna sn.

Choosearryone forcv

Able to state anv two variables co

Mate andnals

a) Able to state all functional materials / 5*materials * 3*apparatusfor the experiment.Materials: *Lemna sp., *distilled water. dilute hvdrochloric acid,

sodium hvdroxide solution, Knop's solution .Apparatus: *Beaker // petri dish // container, nqeasuring cvlinder,

pH piper / meter.

Functionalmaterialsareunderlined

2 Able to state all functional materials / 5*materials f 2*apparatusfor the experiment.Materials: *Lemna sD., *neutral medium , acidic medium, alkaline

medium, Knop's solution .Apparatus: *Beaker // petri dish // container, pH paper / meter.

I Able to state all functional materials lS*materials + l*apparatus forthe experiment.

0 No response / wrong response

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Procedure:

Able to state five procedures PI,P2,P3,P4 and P5 correctly.P1: How to set up the apparatusP2: How to operate the constant variableP3: How to operate the manipulated variable (1P3)P4: How to operate the responding variableP5: Precaution / Accuracv

Able to state three or four of any procedures:Pl /P2 /P3 lP4 lP5correctlv

Able to state two of any procedures :Pll P2/P3/P4lP5 correctly

Able to state one of any procedures PI,PZ, P3, P4 and P5 correctlyNo response / wrong response

Sample answer:I Choose Lemna sp. of the same size.

Pl P2 P2P1P2

2. Choose // take three petri dishes of the same size.P1 P2

P1P2

aJ. Label the petri dishes as A, B and C.

P1P1

4. Pour 5 ml of distilled water into petri dish A, 5 ml of dilute hydrochloric acidinto

Pl P2 P3 P2 P5 P3petri dish B and 5 ml of dilute sodium hydroxide solution into petri dish C.

P2 P5 P3

PIP2P3P5

5. Test the pH value of each solution using pH paper (and record in a table).P3 PI

P1P3

Pour 5 ml of Knop's solution into each petri dish.Pl P2 P2

6. P1P2

Put 5 Lemna sp.Pl P2

into each petri dish.7. P1P2

Record in a table.P1

8. P1

9. Place the petri dishes on the table lnear the window in the laboratory.Pl P2

P1P2

10. Count the number of Lemna sp. after 5 days.P4 P2

P1

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11. Calculate the population growth rate of Lemna sp. by using the formulaP4

Population growth rate: Final number of Lemna sp. - Initial number of Lemna sp.5 davs

P1

12. Repeat the experiment / steps 1 until 11 to get the average resultP5

P1,P2,P4

13. Observe and record the result.P4P4

P5

Able to construct the correct table with titles and units based on three criteria.

Number of Lemna sp.The populationgrowth rate of

Lemna sp. (number

Able to construct the correct table with anv two qiteria.

No response / wrong response

Note:1. Accept any other functional experiments.2. Please take note that variable and data will vary according to that functional experiment.

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