CAPE Biology Unit 1 · 2018 · Paper 2

23 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)4 marksIn the space below, draw AND label the chemical structure of a typical phospholipid molecule, clearly indicating its THREE major components. Label the hydrophilic and hydrophobic parts of the molecule.
2. 1(b)3 marksDescribe how phospholipids are oriented to form the lipid bilayer of cellular membranes.
3. 1(c)1 markState the name of the lipid responsible for maintaining the fluidity of cellular membranes.
4. 1(d)4 marksDescribe how intrinsic proteins allow the movement of substances across cellular membranes.
5. 1(e)(i)1 markIdentify the class of lipids to which the biomolecule in Figure 1 belongs.
6. 1(e)(ii)2 marksExplain how TWO features of the biomolecule in Figure 1 are related to its function in animal tissues.
7. 2(a)(i)3 marksIn Figure 2, insert the appropriate alleles which correspond to the phenotypes of A, B and C given the following characteristics:
8. 2(a)(ii)3 marksDraw a Punnett square in the following box to illustrate a test cross involving a pea variety which is heterozygous for seed type. State the ratio of the phenotypes for the offspring.
9. 2(a)(iii)2 marksDistinguish between 'a gene' and 'an allele'.
10. 2(b)(i)4 marksMake a scaled drawing of the cells labelled D, E and F in Figure 3. Show the magnification of the drawing.
11. 2(b)(ii)3 marksIdentify the cell cycle stages displayed in cells D, E and F in Figure 3.
12. 3(a)(i)3 marksOn the grid provided below, draw a bar chart to compare the concentration of mercury in maternal and foetal blood with the number of maternal amalgam fillings.
13. 3(a)(ii)2 marksState TWO conclusions based on the comparisons shown on the graph.
14. 3(a)(iii)3 marksExplain whether the movement of mercury from mother to foetus is an active or a passive process.
15. 3(b)2 marksWrite the correct labels for A, B, C and D.
16. 3(c)(i)3 marksDescribe the events following pollination which lead to double fertilization.
17. 3(c)(ii)2 marksState the significance of double fertilization to the human diet.
18. 4(a)7 marksWith reference to the structure of enzymes, distinguish between 'competitive inhibition' and 'non-competitive inhibition' with respect to enzyme activity.
19. 4(b)8 marksDiscuss the role of FOUR tissues found in the roots of a plant that support the major functions of the root.
20. 5(a)10 marksWith the aid of a diagram, explain how the information stored in a gene is used to synthesize RNA.
21. 5(b)5 marksUsing an example, briefly explain how proteins are responsible for the phenotype of organisms.
22. 6(a)7 marksOutline the steps involved in plant tissue culture AND explain the key scientific principle underlying this technique.
23. 6(b)8 marksComplete Table 2 by comparing the structure and function of the following FOUR features in a human sperm cell with those of a secondary oocyte.