Answer P : Golgi Apparatus Q: Rough Endoplasmic Reticulum R : Mitochondria
1 1 1
1(a) ( ii ) Able to state the function of R
1
Sample answer R : site for cellular respiration // to generate / produce energy 1 (b )
1
Able to explain how P and Q play the role in transporting extracellular extracellu lar enzyme
4
Sample answer P1 : The nucleus / RNA instructs ribosomes to synthesized protein P2 : The synthesized protein is transported in the Rough Endoplasmic Reticulum / Q P3 : to the transport vesicles P4 : then the Golgi Apparatus / P packages / modifies modifies / sorts / transports the synthesized proteins P5 : to the secretory secretory vesicles to be transported P6 : out of the cell through the plasma membrane Any four 1( c )
1 1 1 1 1 1
Able to explain the importance of the occurrence of the stage to the organism
4
Sample answer P1 :The stage is Prophase 1 P2 : ( During the stage ) Crossing over (occurs between the pair of homologous chromosomes) P3 : (resulting the) gametes (formed to) P4 : (have) different (content of) genetic materials P5 : (thus will cause) variation (in organism) P5 : (for) better adaptation (in the environment) P6 : (greater chance of) survival (of the species) Any 4
Able to state two types of muscles that involved in the movement of an earthworm. Answer 1. Circular muscles 2. Longitudinal muscles Able to explain the circular muscles and longitudinal muscles action that allow the earthworm to move forward. Sample answer P1: Circular muscles and longitudinal longitudinal muscles / both muscles act antagonistically // A pair of antagonistic muscles P2: The contraction of of circular muscles // relaxation of longitudinal muscles P3: Cause the the segments (of the earthworm) to extend / be longer P4: The contraction contraction of longitudinal longitudinal muscles // the relaxation of circular muscles P5: Cause the segments (of the earthworm) to shorten /shorter Any 3 Able to label the pectoralis major muscles. Answer
2(b)
2(c) (i)
2(c)
(iii)
2(d)
Able to state one organelle that can be found abundantly in muscle cells. Answer Mitochondrion / mitochondria Able to explain why muscle cells has abundant number of mitochondrion Sample answer P1: to produce (a lot of) of) energy (in a form of ATP) / ATP P2: for the contraction contraction (and relaxation) of the muscle Able to explain why the bones of a female bird which lay eggs are more brittle as its age increases Sample answer F1 : (Bird’s) bones mass decreases E1 : as the bones are more porous / lighter E2 : (since it had) lay many eggs E3 : 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 re-absorpt ion of calcium / phosphorus / phosphates into the blood stream is more than than the the withdrawing of calcium (during the formation of bones) Any 3 TOTAL
Able to name the cell type that matches its respiration equation
3(b)(i)
Answer: Muscle cells Yeast cells Able to state the types of respiration: Answer: Muscle cells : Aerobic respiration respiration Yeast cells: Anaerobic respiration
3(b)( ii)
3(c)
Marks
2
1 1 2 1 1
Able to state 4 differences in the type of respirat respiration ion Sample answers: Muscle cells Yeast cells Need the presence of Oxygen absent oxygen Complete oxidation of Incomplete oxidation of glucose glucose Occurs in mitochondrion Occurs in cytoplasm More /2898 KJ energy Lesser / 210 KJ energy produced produced Carbon dioxide + Water + Carbon dioxide + Ethanol + 2898 KJ Energy 210 KJ Energy Any 4
4
1 1 1 1 1
Able to explain what happen to the yeast cells when too much ethanol is produced Sample answer P1 : (Too much ethanol ) causes unsuitable unsuitable medium / condition // Toxic / poisonous medium / condition P2 : for yeast cells to reproduced // yeast cells die
3(d)
1 1
Able to explain the condition of a person after completing a 100 meter race in 12 seconds Sample answer F : the person person is panting / higher breathing rate E1 : as he is in oxygen debt // anaerobic respiration E2 : much lactic acid is produced (in his muscle cells) E3 : causes muscle cramp Any two
Able to name the type of response Answer Tropism / phototropism phototropism
3 1
Able to describe the response Sample answer P1 : the plant shoot grows / bends P2 : towards light Able to explain why the plumule grows towards direction X Sample answer E1 : 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 answer E5 : (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 light Any 6 Able to state one difference in the role of auxin in shoot tip compared to root tip. Sample answer P1 : At shoot ( tip, high concentration of ) auxin stimulates cell elongation) elongation) but at root ( tip ) auxin inhibits cell elongation Able to explain one importance of the response to the plant pl ant Sample answer F1 : Positive Phototropism // Negative Geotropism E1 : enables the plant to receive maximum amount of sunlight for photosynthesis // any suitable explanation OR F1 : Negative Phototropism //// Positive Geotropism E1 : enables the root ( hair ) to absorb nutrients / mineral salts from the soil // any suitable explanation TOTAL
Able to state the genotype of the black colour wing and the genotype of the pale and speckled wing Answer Genotype of black colour wing : BB / Bb Genotype of pale and speckled wing : bb
2
1 1
Able to state the dominant trait and give an explanation Sample answer Dominant trait : Black colour wing Explanation : 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.
(e) (i)
Able to explain how the offspring inherits inherit s the pale and speckled wing Sample answer P1 : Both parents are heterozygous / have genotype Bb P2 : during meiosis P3 : the (male) gamete receive allele B or b // the (female) gamete receive allele B or b P4 : during fertilization P5 : 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 Able to state one importance of the difference in wing colour to the moth Sample answer P1 : to have varieties in colour of the moth // variation P2 : better adaptation to the environment // camouflage P3 : better survival of the spesies // Any suitable explanation Any 1 Able to name the process that causes the occurrence
(e) (ii)
Answer Mutation / Deletion / Chromosomal mutation Able to explain how the mutagen causes the occurrence
Sample answer F1 : Mutagen is radioactive radiation / X-ray / formaldehyde / carcinogens / monosodium glutamate // Any suitable example E1 : The mutagen has high penetrating power // high radiation // mutagen able to reach the DNA in the cells / nucleus / chromosomes E2 : causing (drastic) change to the structure of the chromosome E3 : resulting section P to be deleted // gene P to be missing Any 3
4551/2
2
1 1 1 1 12
SULIT
SULIT
4552/2
7
Question 6 No
6(a)
6 (b)
4551/2
Criteria
Marks
Able to explain how glucose is transported transported across the cell through X. Sample Answer: F: By facilitated diffusion diffusion E1: with the aid of carrier protein / X E2: when the concentration concentration of glucose at the outside cell is higher (than inside cell) E3: glucose binds with (the active site of) the carrier protein / X E4 : Carrier protein / X changes shape E5: allowing glucose to move into the cell E6 : Carrier protein resumes / change to its original shape E7 : no energy is needed for the transport process Any 4 Able to explain the absorption and assimilation assimila tion 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 food E2 : 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 energy E6 : amino acids from villi diffuse into blood capillary to the liver via the hepatic portal vein E7 : 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 lacteal E10: then transported to the thoracic duct /right lymphatic vessel// lymphatic vessel E11: to the subclavian veins back to the blood circulatory system E12: fatty acids is synthesized to form the plasma membrane E13 : stored in the adipose tissues (beneath the skin as a source of energy) Any 10
Able to explain how the treatment can help a person to reduce body mass Answer: P1: Small intestine is the site / organ where digestion / absorption absorption of (digested) food occur P2 : Slower rate of hydrolysing of food (to simplest food) P3 : ileum / small small intestine (has intestinal gland to) produce (intestinal juice containing digestive enzymes P4 : shorter ileum has lesser villi / lower surface area P5 : so the rate of diffusion of digested food is slower P6: less digested food is absorbed into blood capillary from the villus P7: the body tissue received less glucose (to undergo cellular respiration) P8: lack of glucose glucose will cause the adipose adipose tissues / stored stored fats to be oxidized/used to produce energy P9: reducing the amount of fats stored // increasing the amount of fats used P10: thus reducing the body mass Any 6
6
1 1 1 1 1 1 1 1 1 1
TOTAL
Question 7 No
7(a)
4551/2
Criteria
Able to explain the how W is formed Sample answer F : When there is cut in the blood vessels E1: (a group of) of) platelets clump / stick stick together E2 : to release trombokinase / thromboplastin E3 : ( thrombokinase / thromboplastin ) converts prothrombin to trombin E4 : ( thrombin ) converts fibrinogen to fibrins / structure W ( fibrins/ W traps erythrocytes / red blood cells ) E5 : then then forms scab ( scab dried) / wound wound is healed Any 4
7( b ) ( i)
20
Able to explain the composition of fluid in P and Q Sample answer F1: Fluid P is red in colour, fluid Q is colourless E1: because fluid P has haemoglobin, fluid Q does not have haemoglobin F2: Fluid P contain red blood cell, fluid Q has no red blood cell E2: because the red blood cells are too large to diffuse / move out of the blood capillary ( to form interstitial interstitial fluid ) F3: Fluid P contain blood blood cells and blood plasma, plasma, fluid Q only contain blood plasma without protein plasma E3: because the protein plasma are too large to diffused out of
the blood capillary F4 : Fluid Q contain more lymphocytes , Fluid P contain less lymphocyes E4 : because as fluid Q flows through the lymphatic nodes , lymphocyes are produced. Any 3 pairs of F and E. 7( b )( ii )
7(c)
4552/2
9
Able to explain how fluid in Q is formed Sample answer F : The blood / the blood capillaries has very high hydrostatic pressure E1: forcing the blood plasma without the plasma proteins / erythrocytes / platelets E2: to diffused out into the spaces between the tissues E3: to form intestitial fluid E4: (90% of the intestitial fluid diffused back into the blood capillary but) 10%/small quantity of the fluid f luid diffused E5: into the lymphatic capillaries ( the vessels with blunt end) E6: forming lymph/lymphatic lymph/lymphatic fluid / fluid Q E7: consisting of blood plasma without protein plasma / contains glucose,water, amino acids, minerals, vitamins ) Any 5 Able to explain the importance of the lymphatic system
1 1
5 1 1 1 1 1 1 1 1
5
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 )
1 1
F2: Acts as a body defence E2: the lymphocytes which are produced in the lymphatic nodes E3: produced antibody E4: spleen produces phagocytes E5: to kill pathogens E6- and filters pathogen Any 5
Able to describe how double fertilization ferti lization occurs in a plant.
10
Sample answers: P1: Anther produces pollen grains / male gamete P2: Pollen mother cell (in the anther) undergoes meiosis to to produce (four) megaspores (n) / haploid cells / tetrad P3: Megaspores (n) / haploid cells / tetrad develop into pollen grains P4: The nucleus of each megaspore (n) / haploid cell / divides by mitosis P5: to form one tube nucleus and one generative nucleus P6: (When a pollen grain falls on the the stigma,) the secretion of sucrose solution on the stigma P7: stimulates (the pollen grain to germinate to) form pollen tube P8: (During the growth of pollen tube) the the generative nucleus divides mitotically P9: 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 nucleus disintegrates disintegrate s and the two male gametes enter the embryo sac. P12: (During double fertilisation) fertilis ation) 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 8(b)
1 1 1 1 1 1 1 1 1 1
1 1 1
Able to describe the advantages of birth control methods in family Sample answers: Contraceptive pill P1: contains oestrogen / progesterone hormone P2: (oestrogen / progesterone hormone) can prevent the formation of follicles in the ovary P3: prevents ovulation ovulation // inhibits the secretion secretion of Follicle Stimulating Hormone / FSH / Luteinising Hormone / LH P4: no fertilization fertiliz ation occur // the woman is not pregnant P5 : efficient / safe method (of birth control)
1 1 1 1 1
Intrauterine device P6: (Intrauterine) (Intrauterine ) device is inserted into the uterus (by doctors). P7: left in the uterus (for approximately two, three and and five years) P8: irritates the endometrium / prevents the the thickening of of the uterine wall
P9: Prevent the implantation of embryo P10: No development of zygote / no pregnancy P11 : efficient/safe method (of birth control) control)
1 1 1
Vasectomy P12: the vas deferens deferens are tied / cut in a surgical operation P13: the sperms are still produced but cannot be transferred transferre d out / reach the uterus / Fallopian tube P14: no fertilization P15 : efficient/safe method (of birth control) (P5, P11 and P15, mark awarded once only) Any 10
1 1 1 1
Total
20
Question 9 No
9(a)
Criteria
Marks
Able to explain the importance importance of maintaining maintaining the biodiversity in the pond ecosystem.
10
Sample answer : F1: as a source of food E1: fish / any suitable example has a high protein content / any suitable food class content F2 : as a source of oxygen supply E2: the green plants undergo photosynthesis ( during photosynthesis oxygen is produced ) F3 : as a source of carbon dioxide supply E4 : the organism undergo respiration (during respiration carbon dioxide is produced ) E5 : a balanced carbon cycle F4 : as a source of clean water supply E6 : the dead organism are decomposed by the bacteria/fungi F5 : interaction between plants and animals E7 : the consumers depend on the producer for food E8 : in the food chain / food web E9 : energy flow from one tropic level to another tropic level F6 : as a habitat for plant /animals /any suitable example E10 : the suitable conditions allow the organism to breed / increase the population / varieties E11: resulting in biodiversity E12 : a balanced ecosystem ecosystem Any 10
Able to discuss how the activities endanger the ecosystem
10
Sample Answer: F1: E1: E2: E3: E4:
( CFC ) causes depletion of ozone layer Penetration of excess/more UV rays Skin cancer/melanoma/sunbur cancer/melanoma/sunburns/catara ns/cataract ct // Any suitable example Reduces body immune system Leaf cells and chlorophyll are easily damaged // Lower rate of photosynthesis E5: Kill microorganisms / phytoplankton E6 : Disruption/destruction of food chain/web E7 : Climatic changes // Any suitable example E8 : Surrounding temperature increases
1 1 1 1 1
F2: ( Combustion of fossil fuel ) causes acid rain // air pollution E7: Factories release a large 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 yield E9: Disruption of food chain / food web E10: Photosynthetic tissues are destroyed// Roots damaged and cannot absorb minerals/water//lower rate of photosynthesis E11: Metal railings / bridges corrode/ any suitable example E12: Health problem: asthma/bronchitis/ and suitable respiratory problem E13: Skin and eye irritation / conjunctivitis conjunctivitis Any 10
