CAPE Biology Unit 1 · 2015 · Paper 2

29 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)3 marksOn the grid in Figure 1, plot the data in Table 1 for the mammalian protease as a line graph.
2. 1(a)(ii)3 marksUsing arrows labelled P1 and P2, indicate, on the x-axis of Figure 1, the temperature at which EACH protease enzyme functions at its maximum efficiency. What accounts for any difference observed?
3. 1(a)(iii)3 marksEnzymes are mainly globular proteins. With reference to the levels of protein organization, explain the effect of temperature on the prokaryote protease between 75 °C and 90 °C.
4. 1(b)1 markFigure 2 is an electron micrograph of a mammalian liver cell.
5. 1(b)(i)3 marksIdentify the organelles labelled I, II and III.
6. 1(b)(ii)1 markIf the actual size of the structure labelled Y is 1.5 µm, calculate the magnification of the electron micrograph in Figure 2.
7. 1(b)(iii)2 marksSuggest a reason which may account for the extensive network of membranes seen in this type of animal cell.
8. 2(a)1 markFigure 3 is a diagram of a cell with four chromosomes (haploid number = 2) during the process of meiosis.
9. 2(a)(i)1 markName the stage of meiosis illustrated in Figure 3.
10. 2(a)(ii)6 marksIn the boxes below, make labelled sketches to illustrate the next TWO key stages of meiosis in this cell. Write the name of the stages on the lines provided below the boxes.
11. 2(a)(iii)3 marksExplain how the key stages identified in (a)(i) and (ii) contribute to genetic variation.
12. 2(b)5 marksExplain how 'substitution' and 'insertion' result in genetic variation. Discuss how gene mutation causes sickle-cell anaemia.
13. 3(a)1 markTable 2 is an incomplete comparison of some features of a human ovum with some features of a spermatozoon.
14. 3(a)(i)6 marksComplete Table 2 by writing the missing information in the relevant spaces in the table.
15. 3(a)(ii)3 marksWith reference to a specific function of the human ovum, discuss how its structure is suited to the stated function.
16. 3(b)1 markFigure 4 is a diagram of a cross section of a fertilized ovule of a flowering plant.
17. 3(b)(i)1 markOn Figure 4, indicate, using an arrow labelled X, the structure which will develop a radicle and plumule.
18. 3(b)(ii)2 marksIdentify the structure labelled Y and explain its role in the developing embryo.
19. 3(b)(iii)3 marksAn orange is described as a fleshy fruit. Name the part of a flowering plant which develops into a fleshy fruit after the ovule has been fertilized. Comment on the importance of the fruit, such as an orange, in the life…
20. 4(a)(i)4 marksWith the aid of an annotated diagram, describe the structure of phospholipids.
21. 4(a)(ii)5 marksWith reference to the fluid mosaic model, discuss the role of phospholipids and proteins in cell membrane functioning.
22. 4(b)6 marksUsing a generalized structure for amino acids, outline the process of formation of a peptide bond between two amino acids. Explain, using an example, how amino acids differ from each other.
23. 5(a)5 marksExplain what is meant by the term 'gene'. Outline the principles of using restriction enzymes to cut a gene from a length of DNA. Note: Details of the steps involved in recombinant DNA technology are not required.
24. 5(b)1 markGene therapy is the application of the principle of genetic engineering in the treatment of diseases.
25. 5(b)(i)2 marksGive a brief description of one human disease for which the use of somatic gene therapy has been shown to be effective.
26. 5(b)(ii)8 marksDiscuss FOUR reasons why somatic gene therapy, despite its potential, is still not used as an effective treatment for human diseases.
27. 6(a)(i)4 marksExplain TWO mechanisms for the promotion of cross-fertilization in plants.
28. 6(a)(ii)7 marksEvaluate the genetic consequences of self-fertilization and cross-fertilization in plants.
29. 6(b)4 marksStarting with contact of sperm cells with follicle cells of the oocyte, outline the process of fertilization in the human reproductive system.