PROGRAM PENINGKATAN PRESTASI AKADEMIK SPM2010

BIOLOGY MARK SCHEME

PAPER 2

JABATAN PELAJARAN NEGERI SELANGORPERSIDANGAN KEBANGSAAN PENGETUA SEKOLAH

MENENGAH

Question 1QuestionNum

Criteria MarksSub Total

1(a) ( i ) Able to name structures P,Q and R

AnswerP : Golgi ApparatusQ: Rough Endoplasmic ReticulumR : Mitochondria

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3

1(a) ( ii ) Able to state the function of R

Sample answer

R : site for cellular respiration // to generate / produce energy 1

1

1 (b ) Able to explain how P and Q play the role in transporting extracellular enzyme

Sample answer

P1 : The nucleus / RNA instructs ribosomes to synthesized proteinP2 : The synthesized protein is transported in the Rough Endoplasmic Reticulum / QP3 : to the transport vesiclesP4 : then the Golgi Apparatus / P packages / modifies / sorts / transports the synthesized proteins P5 : to the secretory vesicles to be transportedP6 : out of the cell through the plasma membraneAny four

1

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1( c ) Able to explain the importance of the occurrence of the stage to the organism

Sample answer

P1 :The stage is Prophase 1P2 : ( During the stage ) Crossing over (occurs between the pair of homologous chromosomes)P3 : (resulting the) gametes (formed to)P4 : (have) different (content of) genetic materialsP5 : (thus will cause) variation (in organism)P5 : (for) better adaptation (in the environment)P6 : (greater chance of) survival (of the species)Any 4

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4

Total 12

Pectoralis Major Muscles

Question 2No Criteria Marks

2(a) Able to state two types of muscles that involved in the movement of an earthworm.Answer1. Circular muscles2. Longitudinal muscles

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2(b) Able to explain the circular muscles and longitudinal muscles action that allow the earthworm to move forward.Sample answerP1: Circular muscles and longitudinal muscles / both muscles act antagonistically // A pair of antagonistic musclesP2: The contraction of circular muscles // relaxation of longitudinal musclesP3: Cause the segments (of the earthworm) to extend / be longerP4: The contraction of longitudinal muscles // the relaxation of circular muscles P5: Cause the segments (of the earthworm) to shorten /shorterAny 3

1

1

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2(c) (i) Able to label the pectoralis major muscles.Answer

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1

2(c) (ii) Able to state one organelle that can be found abundantly in muscle cells.AnswerMitochondrion / mitochondria 1

1

2(c) (iii) Able to explain why muscle cells has abundant number of mitochondrionSample answerP1: to produce (a lot of) energy (in a form of ATP) / ATPP2: for the contraction (and relaxation) of the muscle

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2

2(d) Able to explain why the bones of a female bird which lay eggs are more brittle as its age increasesSample answerF1 : (Bird’s) bones mass decreasesE1 : as the bones are more porous / lighterE2 : (since it had) lay many eggsE3 : much calcium / phosphorus / phosphates used in forming the

shells of the eggs E4 : leaving less / little calcium / phosphorus / phosphates used to form

(strong) bones // more bone minerals to be lost than deposited // re-absorption of calcium / phosphorus / phosphates into the blood stream is more than the withdrawing of calcium (during the formation of bones)

Any 3

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TOTAL 12

Question 3No Criteria Marks

3 (a) Able to name the cell type that matches its respiration equation

Answer:Muscle cellsYeast cells

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2

3(b)(i) Able to state the types of respiration: Answer:Muscle cells : Aerobic respirationYeast cells: Anaerobic respiration

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2

3(b)( ii) Able to state 4 differences in the type of respirationSample answers:

Muscle cells Yeast cellsNeed the presence of oxygen

Oxygen absent

Complete oxidation of glucose

Incomplete oxidation of glucose

Occurs in mitochondrion Occurs in cytoplasmMore /2898 KJ energy produced

Lesser / 210 KJ energy produced

Carbon dioxide + Water + 2898 KJ Energy

Carbon dioxide + Ethanol + 210 KJ Energy

Any 4

1

1

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3(c) Able to explain what happen to the yeast cells when too much ethanol is produced

Sample answerP1 : (Too much ethanol ) causes unsuitable medium /

condition // Toxic / poisonous medium / conditionP2 : for yeast cells to reproduced // yeast cells die

1

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2

3(d) Able to explain the condition of a person after completing a 100 meter race in 12 seconds

Sample answerF : the person is panting / higher breathing rateE1 : as he is in oxygen debt // anaerobic respirationE2 : much lactic acid is produced (in his muscle cells)E3 : causes muscle crampAny two

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2

TOTAL 12

Question 4No Criteria Marks

Sub Total4 a ( i ) Able to name the type of response

AnswerTropism / phototropism

Able to describe the responseSample answerP1 : the plant shoot grows / bendsP2 : towards light

1

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3

4 b ( i )

4 b ( ii )

Able to explain why the plumule grows towards direction XSample answerE1 : auxin stimulates / promotes cell elongation at the shoot ( tip )E2 : more auxin is distributed at the darker / lower side of the shoot (tip comparing to the bright / upper side)E3 : (so at the darker / lower side) the rate of cell elongation is higher (than the bright / upper side) E4 : the shoot ( tip ) grows / bends towards light /away from gravity.

Able to explain why the radicle grows towards direction Y.Sample answerE5 : (High concentration of) auxin inhibits cell elongation at radicle /

root ( tip )E6 : more auxin is distributed at the lower / darker side of the root ( tip

comparing to the upper / brighter side)E7 : so at the lower / darker side of the root ( tip ) the rate of cell

elongation is slower (than the brighter / upper side) E8 : so the root grows / bends downward toward gravity / away from

lightAny 6

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1

1

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1

1

6

4 ( c ) Able to state one difference in the role of auxin in shoot tip compared to root tip.Sample answerP1 : At shoot ( tip, high concentration of ) auxin stimulates cell elongation) but at root ( tip ) auxin inhibits cell elongation

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1

4 ( d ) Able to explain one importance of the response to the plant

Sample answerF1 : Positive Phototropism // Negative Geotropism E1 : enables the plant to receive maximum amount of sunlight for photosynthesis // any suitable explanationORF1 : Negative Phototropism // Positive GeotropismE1 : enables the root ( hair ) to absorb nutrients / mineral salts from the soil // any suitable explanation

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TOTAL 12

Question 5No Criteria Marks

5(a) Able to state the genotype of the black colour wing and the genotype of the pale and speckled wing AnswerGenotype of black colour wing : BB / BbGenotype of pale and speckled wing : bb

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2

( b ) Able to state the dominant trait and give an explanation Sample answerDominant trait : Black colour wingExplanation :E1 : More number of moth are black colour // There are three black colour moth and only one pale and speckled wing // 75 % of the

moth have black colour wing while 25% of the moth have pale and speckled wing // The presence of dominant gene / B.

1

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2

( c ) Able to explain how the offspring inherits the pale and speckled wingSample answerP1 : Both parents are heterozygous / have genotype BbP2 : during meiosisP3 : the (male) gamete receive allele B or b // the (female) gamete receive allele B or bP4 : during fertilizationP5 : the male gamete with allele b fused with female gamete with allele b (so the offspring has genotype bb // pale and speckled wing) Any 3

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3

( d ) Able to state one importance of the difference in wing colour to the mothSample answerP1 : to have varieties in colour of the moth // variationP2 : better adaptation to the environment // camouflageP3 : better survival of the spesies // Any suitable explanationAny 1

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1

(e) (i) Able to name the process that causes the occurrence

AnswerMutation / Deletion / Chromosomal mutation

1

1

(e) (ii) Able to explain how the mutagen causes the occurrence

Sample answerF1 : Mutagen is radioactive radiation / X-ray / formaldehyde / carcinogens

/ monosodium glutamate // Any suitable exampleE1 : The mutagen has high penetrating power // high radiation // mutagen

able to reach the DNA in the cells / nucleus / chromosomesE2 : causing (drastic) change to the structure of the chromosomeE3 : resulting section P to be deleted // gene P to be missing Any 3

1

1

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3

TOTAL 12

Question 6No Criteria Marks

6(a) Able to explain how glucose is transported across the cell through X.Sample Answer:

F: By facilitated diffusionE1: with the aid of carrier protein / XE2: when the concentration of glucose at the outside cell is higher

(than inside cell)E3: glucose binds with (the active site of) the carrier protein / XE4 : Carrier protein / X changes shapeE5: allowing glucose to move into the cellE6 : Carrier protein resumes / change to its original shapeE7 : no energy is needed for the transport process Any 4

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6 ( b ) Able to explain the absorption and assimilation of digested food.Sample Answers: F1 : ileum has (the adaptive features such as having) many villi /

villus / very thin cell wall / villus are surrounded by dense network of blood capillary / lacteal

E1 : to increase the rate of diffusion of the digested foodE2 : glucose diffused from villi into the blood capillary to the liver

via the hepatic portal vein E3 : excess glucose is converted to glycogen (to be kept in the

liver)E4 : glycogen acts as stored food E5 : In body tissue,glucose is oxidized during cellular respiration

to produced energyE6 : amino acids from villi diffuse into blood capillary to the liver

via the hepatic portal veinE7 : excess amino acids is deaminated / converted into urea (to

be excreted through the kidney)E8 : amino acid will be used to synthesis new protoplasm / repair

of damaged tissues// used to synthesis proteins of plasma membrane//produce enzymes/antibodies/hormones

E9 : fatty acids diffuse from villi into lactealE10: then transported to the thoracic duct /right lymphatic vessel// lymphatic vesselE11: to the subclavian veins back to the blood circulatory systemE12: fatty acids is synthesized to form the plasma membraneE13 : stored in the adipose tissues (beneath the skin as a source of energy)Any 10

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1

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10

6 ( c ) Able to explain how the treatment can help a person to reduce body mass

6

Answer:P1: Small intestine is the site / organ where digestion /

absorption of (digested) food occurP2 : Slower rate of hydrolysing of food (to simplest food) P3 : ileum / small intestine (has intestinal gland to) produce (intestinal juice containing digestive enzymesP4 : shorter ileum has lesser villi / lower surface areaP5 : so the rate of diffusion of digested food is slower P6: less digested food is absorbed into blood capillary from the villusP7: the body tissue received less glucose (to undergo cellular respiration)P8: lack of glucose will cause the adipose tissues / stored fats to

be oxidized/used to produce energyP9: reducing the amount of fats stored // increasing the amount of fats usedP10: thus reducing the body mass Any 6

1

11

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1

1

1

1

TOTAL 20

Question 7No Criteria Marks

7 ( a ) Able to explain the how W is formedSample answerF : When there is cut in the blood vessels E1: (a group of) platelets clump / stick togetherE2 : to release trombokinase / thromboplastinE3 : ( thrombokinase / thromboplastin ) converts prothrombin to trombinE4 : ( thrombin ) converts fibrinogen to fibrins / structure W ( fibrins/ W traps erythrocytes / red blood cells )E5 : then forms scab ( scab dried) / wound is healedAny 4

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1

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4

7( b ) ( i) Able to explain the composition of fluid in P and QSample answerF1: Fluid P is red in colour, fluid Q is colourlessE1: because fluid P has haemoglobin, fluid Q does not have haemoglobinF2: Fluid P contain red blood cell, fluid Q has no red blood cellE2: because the red blood cells are too large to diffuse / move

out of the blood capillary ( to form interstitial fluid )F3: Fluid P contain blood cells and blood plasma, fluid Q only contain blood plasma without protein plasmaE3: because the protein plasma are too large to diffused out of the blood capillaryF4 : Fluid Q contain more lymphocytes , Fluid P contain less

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1

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6

lymphocyesE4 : because as fluid Q flows through the lymphatic nodes , lymphocyes are produced.Any 3 pairs of F and E.

1

7( b )( ii ) Able to explain how fluid in Q is formedSample answerF : The blood / the blood capillaries has very high hydrostatic

pressureE1: forcing the blood plasma without the plasma proteins /

erythrocytes / plateletsE2: to diffused out into the spaces between the tissuesE3: to form intestitial fluidE4: (90% of the intestitial fluid diffused back into the blood capillary but) 10%/small quantity of the fluid diffused E5: into the lymphatic capillaries ( the vessels with blunt end)E6: forming lymph/lymphatic fluid / fluid QE7: consisting of blood plasma without protein plasma / contains glucose,water, amino acids, minerals, vitamins )Any 5

1

1

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7 ( c ) Able to explain the importance of the lymphatic system

F1: maintaining the composition of blood E1: the 10%/ small quantity of the interstitial/body fluid / blood

plasma without the protein plasma diffused back (from the lymphatic system) into the blood circulatory system ( diffused into the right and left subclavian veins from the right lymphatic duct and the thoracic duct )

F2: Acts as a body defenceE2: the lymphocytes which are produced in the lymphatic nodesE3: produced antibodyE4: spleen produces phagocytesE5: to kill pathogensE6- and filters pathogenAny 5

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TOTAL 20

Question 8

No Criteria Marks8(a) Able to describe how double fertilization occurs in a plant.

Sample answers:

P1: Anther produces pollen grains / male gameteP2: Pollen mother cell (in the anther) undergoes meiosis to produce (four) megaspores (n) / haploid cells / tetradP3: Megaspores (n) / haploid cells / tetrad develop into pollen grainsP4: The nucleus of each megaspore (n) / haploid cell / divides by mitosis P5: to form one tube nucleus and one generative nucleusP6: (When a pollen grain falls on the stigma,) the secretion of sucrose solution on the stigma P7: stimulates (the pollen grain to germinate to) form pollen tubeP8: (During the growth of pollen tube) the generative nucleus divides mitoticallyP9: to produce two male gametes.P10: the two male gametes move/follow behind the tube nucleus (down

the pollen tube until they) reach the micropyle and enter ovule (for double fertilization)P11: the tube nucleus disintegrates and the two male gametes enter the

embryo sac.P12: (During double fertilisation) one male gamete fuses with the egg cell/ovum to form a diploid zygote and P13: the other male gamete fuses with the two polar nuclei to form a triploid nucleus (so double fertilization occurs ) Any 10

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10

8(b) Able to describe the advantages of birth control methods in family

Sample answers:

Contraceptive pillP1: contains oestrogen / progesterone hormoneP2: (oestrogen / progesterone hormone) can prevent the formation of follicles in the ovary P3: prevents ovulation // inhibits the secretion of Follicle Stimulating Hormone / FSH / Luteinising Hormone / LH P4: no fertilization occur // the woman is not pregnantP5 : efficient / safe method (of birth control)

Intrauterine deviceP6: (Intrauterine) device is inserted into the uterus (by doctors).P7: left in the uterus (for approximately two, three and five years)P8: irritates the endometrium / prevents the thickening of the uterine wallP9: Prevent the implantation of embryo P10: No development of zygote / no pregnancy

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P11 : efficient/safe method (of birth control)

VasectomyP12: the vas deferens are tied / cut in a surgical operationP13: the sperms are still produced but cannot be transferred out / reach the uterus / Fallopian tubeP14: no fertilization P15 : efficient/safe method (of birth control)(P5, P11 and P15, mark awarded once only)Any 10

1

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Total 20

Question 9No Criteria Marks

9(a) Able to explain the importance of maintaining the biodiversity in the pond ecosystem.

Sample answer :

F1: as a source of food E1: fish / any suitable example has a high protein content / any suitable food class contentF2 : as a source of oxygen supplyE2: the green plants undergo photosynthesis ( during photosynthesis oxygen is produced ) F3 : as a source of carbon dioxide supplyE4 : the organism undergo respiration (during respiration carbon dioxide is produced )E5 : a balanced carbon cycleF4 : as a source of clean water supplyE6 : the dead organism are decomposed by the bacteria/fungiF5 : interaction between plants and animalsE7 : the consumers depend on the producer for foodE8 : in the food chain / food webE9 : energy flow from one tropic level to another tropic levelF6 : as a habitat for plant /animals /any suitable exampleE10 : the suitable conditions allow the organism to breed / increase the population / varieties E11: resulting in biodiversity E12 : a balanced ecosystem

Any 10

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9(b) Able to discuss how the activities endanger the ecosystem 10

Sample Answer: F1: ( CFC ) causes depletion of ozone layerE1: Penetration of excess/more UV rays E2: Skin cancer/melanoma/sunburns/cataract // Any suitable exampleE3: Reduces body immune systemE4: Leaf cells and chlorophyll are easily damaged // Lower rate of

photosynthesisE5: Kill microorganisms / phytoplanktonE6 : Disruption/destruction of food chain/web E7 : Climatic changes // Any suitable example E8 : Surrounding temperature increases

F2: ( Combustion of fossil fuel ) causes acid rain // air pollutionE7: Factories release a large amount of nitrogen oxide/nitrogen dioxide/sulphur dioxide/carbon monoxides / dust in the

atmosphere.E8: Acid rain – soil become acidic (so less suitable for the cultivation of certain crops) // lower yieldE9: Disruption of food chain / food webE10: Photosynthetic tissues are destroyed// Roots damaged and cannot absorb minerals/water//lower rate of photosynthesisE11: Metal railings / bridges corrode/ any suitable exampleE12: Health problem: asthma/bronchitis/ and suitable respiratory problemE13: Skin and eye irritation / conjunctivitis Any 10

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TOTAL 20