Biology 2014
4.4.1 Biology Paper 1 (231/ 1)
1. (a) Acquisition and utilization of nutrients; (1 mark)
(b) Elimination of metabolic wastes to prevent accumulation to toxic level; (1 mark)
2. (a) A period of rest in which a seed performs its physiological processes slowly and utilizes little food; (1 mark)
(b) – Chemical/growth inhibitors;
– Hard/impermeable seed coat;
– Low / freezing temperatures;
– Under developed embryo/immature embryo;
– Low concentration of hormones;
– Lack of appropriate light wavelength;
(max 3 marks)
3. – Exchange of nutrients /metabolic wastes/ gases between the mother and foetal circulatory systems;
– Secretion of progesterone hormone;
(2 marks)
4. (a) Tube nucleus;
(b) – One male nucleus fuses with the egg cell nucleus to form a zygote;
– The other male nucleus fuses with the polar nuclei to form the endosperm;
(2 marks)
5. (a) Hypertonic solution; (1 mark)
(b) Volume of sugar solution increases in the thistle funnel While that of distilled water in the beaker reduces; because the thistle funnel gains distilled water by osmosis.
(2 marks)
6. – Cell division;
– Cell elongation;
– Development of adventitious roots;
– Formation of callus tissue;
– Causes apical dominance;
– Causes tropic responses.
3 x 1 (3 marks)
7. Object length = 12 cm
Drawing length = 6 cm
M _ Drawing length _ _i_
g — Object length ’ — 12 ’
= X 0.5;
(2 marks)
8. – Phenotype is the outward appearance of an organism while Genotype is the genetic make up of an organism; (1 mark)
9. – Act as shock absorbers;
– Allow smooth movement between the vertebrae/reduce friction; (2 marks)
10. (a) – Absorption of materials e.g. diffusion of digested food into the blood stream;
– Gaseous exchange e.g. CO2/O2 diffuses from capillaries into the alveoli.
– Excretion of nitrogenous Wastes; e.g urea diffuses from blood capillaries into the elimination sites. (max 4 marks)
(b) (i) Crenated cell is a shrunk animal cell that has lost water by osmosis; (1 mark)
(ii) Flaccid cell is a flabby /shrunk plant cell that has lost waster by osmosis; (1 mark)
11. Tactic Responses Tropic Response
– Are locomotory – Are growth responses;
– Are fast – Are slow;
– Not influenced by growth hormones – Are caused by growth hormones;
– Temporary – Permanent;
(3 marks)
12. (a) (i) Rib-cage/chest cavity; ( 1 mark)
(ii) Diaphragm; (1 mark)
(b) The balloons are inflated; (1 mark)
(c) Pulling down the string increases the volume of D, hence decreasing the pressure inside;
The low pressure causes external atmospheric air to rush in and inflate the balloons; (2 marks)
13. (a) Trap foreign particles entering the eye;
Produce fluid/tears; (1 mark)
(b) – Moistens the comea;
– Wash foreign materials out of the eye;
– Antiseptic / kills harmful microorganisms; ‘ ‘ ‘ ‘
14. DNA RNA
Double stranded/double relix Single stranded;
Has Thymine Thymine is replaced by uracil/reject Thiamin;
Has the four nitrogen base pairing pattern Lack the four nitrogen base pairing pattern;
Deoxyribose sugar Ribose sugar;
(3 marks)
15. (a) Skeletal muscles / striated muscles; (1 mark)
(b) Tendon is a (inelastic) tissue that attaches muscles to bones while Ligament is a (inelastic) tissue that attaches a bone to another bone of a movable joint;
(1 mark)
16. (a) Sensory neurone; (1 mark)
(b) Cell body is located off the axon/tied outside the CNS; (1 mark)
(c) Schwann cell; (1 mark)
(d) (i) Receipt/transmits impulses to neighbouring neurons in the CNS from sense organs; (1 mark)
(ii) Insulates the axon/accept dendron for axon; (1 mark)
17. The blind spot lacks both cones and rods hence images are not perceived; (1 mark)
Accept photoreceptor cells for cones and rods;
18. (a) To provide a cool environment; that is conducive for sperm formation; (2 marks)
(b) Progesterone hormone; is secreted by the placenta to maintain the pregnancy; (2 marks)
19. Due to limited oxygen, haemoglobin combines With carbon (II) oxide to form carboxyhaemoglobin;
Carboxyhaemoglobin does not readily dissociate hence reduces the capacity of haemoglobin to transport oxygen; Carbon (II) oxide is therefore a respiratory poison if breathed in for a long time;
(3 marks)
20. (a) Packaging of substances/glycoproteins/ transportation of glycoproteins; Secretion of synthesized proteins and carbohydrates;
Formation of lysosomes/modification of carbohydrates to form glycoproteins; (1 mark)
(b) – Digestion of food/Breakdown large molecules;
– Destroy Worn out organelles or cells/tissue;
(max 1 mark)
21. (a) Exoskeleton;
(b) Endoskeleton; ( 1 mark)
22. (a) Appendix/accept nictating membrane; coecum and ear drum;
Tail/coccyx; ( 1 mark)
(b) They have a gene for resistance/acquire it through mutation;
The gene for resistance is passed to offsprings establishing a population of resistant forms;
(2 marks)
23. (a) K – Photosynthetic products/manufactured foods example vitamins/alicose/proteins/ sucrose/maltose/fructose/lipids/nitrates; ( 1 mark)
L – Water and mineral salts; (1 mark)
(b) The substances are moved into the star shaped xylem; (1 mark)
24. M – lungs; (1 mark)
N – Urea,ammonia,; (1 mark)
P – Digested food,Water; mineral ions; (1 mark)
25. – Stimulates maturation of the Graafian follicle/stimulates ovulation;
– Stimulates corpus luteum to secrete progesterone hormone;
– Stimulates release of androgens;
– Stimulates development of corpus luteum;
(2 marks)
26. (a) (i) Diffusion; ( 1 mark)
(ii) Sea water contains a higher concentration of sodium ions than the cell sap; (1 mark)
(b) (i) Iodide ions; (1 mark)
(ii) Sea water has a lower concentration of iodide ions than the cell.
The plant requires energy to take up the iodide ions (by active transport); (1 mark)
27. (a) Spiracle; ( mark)
(b) Keep the trachea open for air passage; ( mark)
(c) – Lacks spiral bands of chitin / to make it thin; for diffusion of gases
– Moist; to dissolve respiratory gases;
(2 marks)
