CSEC Biology · January 2009 · Paper 2

42 questions and parts from this paper. Open one to see it in full, then practise it on Quelpr and get it marked against the mark scheme.

1. 1(a)(i)4 marksUsing the data in Table 1, complete the graph on page 3 to show the rate of reaction of Enzymes X and Y at the different pH levels.
2. 1(a)(ii)1 markGive ONE reason why the rate of reaction for both enzymes was sometimes zero.
3. 1(a)(iii)a)6 marksWhat is the optimum pH for Enzyme X? What is the optimum pH for Enzyme Y?
4. 1(a)(iii)b)1 markWhich enzyme functions at a lower pH range?
5. 1(a)(iii)c)1 markWhich enzyme produces more products at its optimum pH?
6. 1(a)(iii)d)1 markIs it likely that Enzyme X and Enzyme Y are similar? Give ONE reason for your answer.
7. 1(b)5 marksThe product of reactions catalyzed by Enzymes X and Y is a reducing sugar. Describe a test the students could use to confirm the presence of the reducing sugar. Give the apparatus and materials to be used and describe…
8. 1(c)(i)2 marksAlthough they are produced by different organs in the human digestive system, Enzymes X and Y break down the same nutrient in the body. Identify Enzymes X and Y.
9. 1(c)(ii)2 marksLabel the diagram in Figure 1 to show where Enzymes X and Y are found.
10. 1(c)(iii)2 marksSuggest TWO advantages to humans of having two forms of the same enzyme.
11. 1(d)(i)1 markIdentify ONE condition or circumstance when digestion of food takes place in a plant.
12. 1(d)(ii)2 marksName TWO inorganic substances (mineral elements) required by plants to make their food.
13. 2(a)(i)3 marksIdentify the regions indicated by the lines numbered 1-3.
14. 2(a)(ii)2 marksIdentify from the diagram TWO structures which aid in temperature regulation in humans.
15. 2(a)(iii)2 marksState TWO functions of the skin other than temperature regulation.
16. 2(b)(i)4 marksMr Firebon was badly burnt and lost all of Region 1 shown in Figure 2 on page 6. Suggest TWO ways in which the functioning of the skin would be affected.
17. 2(b)(ii)2 marksSometimes burns are treated by grafting onto the burnt area skin taken from another part of a person's own body. Outline ONE advantage of this procedure.
18. 2(c)2 marksSuggest ONE reason why a plant may also need to regulate its temperature.
19. 3(a)(i)3 marksComplete the chart in Figure 3, using letters and words as appropriate, to show the inheritance of flower colour when two pure-breeding varieties of Impatiens are crossed. The heterozygous phenotype is pink.
20. 3(a)(ii)2 marksIf F₁ Impatiens plants were crossed, what would be the phenotypic ratio for flower colour in the offspring?
21. 3(a)(iii)3 marksWhat type of genetic variation is shown by the flower colour in Impatiens? Explain your answer.
22. 3(b)(i)2 marksThe alleles of the ABO blood group in humans show co-dominance. How does this co-dominance differ from incomplete dominance shown in the inheritance of flower colour in Impatiens illustrated in Figure 3?
23. 3(b)(ii)1 markIf the Impatiens flowers in Figure 3 showed co-dominance, what would be the phenotype of the F₁ generation?
24. 3(b)(iii)4 marksIn the space provided below, show, by using a genetic diagram, how a child may inherit blood type O from parents who belong to blood groups A and B respectively.
25. 4(a)6 marksWith the aid of a balanced equation, describe the process by which green plants make their food.
26. 4(b)(i)4 marksTomato plants infested with a population of caterpillars
27. 4(b)(ii)1 markWater plants rooted to the bottom of a pond in which there is a proliferation (sudden large population) of algae
28. 4(c)(i)5 marksHow does the use of fertilisers increase crop yield?
29. 4(c)(ii)1 markSome farmers choose to use chemical fertilisers, while others use natural fertilisers. Suggest TWO disadvantages of the use of chemical fertilisers.
30. 4(c)(iii)1 markSuggest ONE beneficial effect of organic fertilisers on soil.
31. 5(a)(i)6 marksDescribe the process of respiration in living cells.
32. 5(a)(ii)1 markHow do the cells in the human body obtain the raw materials for respiration?
33. 5(b)(i)7 marksIdentify TWO likely symptoms of persons suffering from anaemia.
34. 5(b)(ii)a)1 markHow is the oxygen-carrying capacity of the blood reduced by sickle-cell anaemia?
35. 5(b)(ii)b)1 markHow is the oxygen-carrying capacity of the blood reduced by iron-deficiency anaemia?
36. 5(b)(iii)1 markSuggest TWO ways of treating persons suffering from iron-deficiency anaemia.
37. 5(c)2 marksSuggest ONE reason why some persons with diseases have higher than normal numbers of white blood cells.
38. 6(a)6 marksUsing annotated diagrams, compare the structure of a wind-pollinated flower with that of an insect-pollinated flower.
39. 6(b)(i)6 marksExplain TWO ways in which humans make use of the plants' ability to reproduce asexually.
40. 6(b)(ii)1 markGive TWO advantages to humans of asexual reproduction in plants.
41. 6(c)(i)3 marksSuggest TWO likely risks involved in transporting living plant material from one territory to another.
42. 6(c)(ii)1 markAgricultural produce is imported from one territory to another. Suggest ONE way in which the risks in this activity can be reduced.