1. INTERACTIVE MULTIPLE CHOICE QUESTIONS The answers are provided, but so also are explanations of why the alternatives are unsatisfactory © D.G. Mackean Principles of Biology

2. These multiple choice questions are similar to the ones set by the GCSE and IGCSE Examination Boards except that, in some cases, there may be more than one acceptable answer. For this reason, even if you select a correct answer at your first attempt, it is worth looking at all the alternatives (a) to see if there is a better answer and (b) to see why some of the alternatives are unacceptable. Question 1

3. The drawings represent stages in division of an animal cell. a b cd (a) b, d, a, c (b) b, d, c, a (c) b, a, c, d (d) b, c, d, a Question 2 Which of the following is the correct sequence of events?

4. Yes This the correct sequence

5. The cell constricts ( a ) before the cells separate ( c ) No

6. The nucleus divides ( d ) before the cell starts to constrict ( a ) No

7. The separation into two cells is the final stage No

8. Question 2 The drawing represents a typical leaf cell from a plant. What structure or structures are missing from the drawing? (a) cell wall (b) cytoplasm (c) nucleus (d) chloroplasts Question 3

9. cell wall No The cell wall is present

10. cytoplasm No The cytoplasm is present

11. Yes nucleus The nucleus was omitted from the drawing

12. No The chloroplasts are present chloroplasts

13. Question 3 After being exposed to temperatures ranging from 50-60ºC, most enzyme cannot function because … (a) their molecules have been broken down (b) their molecules have changed shape(c) their composition has been changed (d) they cannot separate from their substrate Question 4

14. The molecules remain intact at these temperatures No

15. The molecules have been denatured. That is, their shape has changed so that they can no longer bind to their substrate Yes

16. The composition of the enzyme molecule is usually unaltered at these temperatures No

17. They are unable to combine with their substrate No

18. Question 4 Which of these statements is correct? The enzyme amylase … (a) breaks down starch and protein(b) works best at 50ºC (c) breaks down starch only(d) breaks down cellulose Question 5

19. No Enzymes act on only one type of substrate

20. No Most enzymes are denatured (inactivated) at this temperature

21. Yes Amylase acts on starch, breaking it down to maltose

22. No The enzyme which breaks down cellulose would be a cellulase

23. Question 5 In biology, the term respiration means … (d) A procedure used to revive a person who has stopped breathing (c) releasing energy from carbohydrates by combing them with oxygen (b) the release of energy from food substances (a) the act of breathing Question 6

24. No The act of breathing is called ventilation. It is a method of obtaining oxygen for aerobic respiration

25. Yes The release of energy from the breakdown of food substances, such as glucose, is called respiration

26. Partly right But this definition applies only to aerobic respiration. Energy can also be released from food by anaerobic respiration for which oxygen is not needed.

27. No Reviving a person who has stopped breathing is called resuscitation. In First Aid this is done by the ‘mouth to mouth’ method. An outdated method, depending on compression of the thorax was called (misleadingly) ‘artificial respiration’

28. Question 6 Which of the following is NOT reliable evidence of respiration in a land-dwelling organism (d) Loss of dry mass (c) Uptake of oxygen (b) Production of water vapour (a) Output of carbon dioxide Question 7

29. This is reliable evidence The equation for aerobic respiration C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O shows that production of carbon dioxide is good evidence of respiration

30. Although the equation for aerobic respiration C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O shows that water is a product of respiration it is not good evidence of respiration because non-living material can produce water vapour by evaporation alone This is not reliable evidence

31. The equation for aerobic respiration C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 0 shows that uptake of oxygen is good evidence of respiration. Admittedly, anaerobic respiration does not consume oxygen but it seems unlikely that a land dwelling organism would be using anaerobic respiration exclusively This is reliable evidence

32. Although the equation C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 0 shows glucose as the respiration substrate, almost any tissues can be used for respiration so a loss in dry mass means respiration is occurring. It has to be dry mass to avoid the loss of mass associated with evaporation

33. Question 7 In a green plant, when the rates of respiration and photosynthesis are equal the plant will be …. (a) taking in carbon dioxide (d) giving out water vapour (b) giving out oxygen (c) taking in carbon dioxide and giving out oxygen Question 8

34. No The carbon dioxide needed for photosynthesis will all come from respiration 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 (photosynthesis) C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O (respiration)

35. No All the oxygen produced by photosynthesis will be used for respiration 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 (photosynthesis) C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O (respiration)

36. No There will be no net uptake of carbon dioxide or output of oxygen. All the carbon dioxide needed for photosynthesis will come from respiration, and the oxygen produced by photosynthesis will be used in respiration 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 (photosynthesis) C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O (respiration)

37. There will be no net uptake of carbon dioxide or output of oxygen. All the carbon dioxide needed for photosynthesis will come from respiration, and the oxygen produced by photosynthesis will be used in respiration. (See previous slide). However, the plant will be transpiring and there will be a loss of water vapour Yes

38. Question 8 Which of the structures in these palisade cells from a leaf is responsible for photosynthesis? 1 2 3 4 (d) 4 (c) 3 (b) 2 (a) 1 Question 9

39. Yes This structure is a chloroplast and is the site of photosynthesis

40. No This structure is the nucleus. It controls the activities in the cell but does not photosynthesize

41. No This is the vacuole. It may store sugars produced in photosynthesis but it does not photosynthesize

42. No This is the cytoplasm. Most of the chemical processes of the cell occur in the cytoplasm, but not photosynthesis

43. Question 9 Which of the following mineral ions does a plant need for making proteins? (a) Phosphate ions (b) Potassium ions (c) Nitrate ions (d) Magnesium ions Question 10

44. No Phosphate ions are needed for making DNA and for many enzyme reactions, but do not form part of proteins

45. No Potassium ions are needed for certain reactions in the plant cell, including those leading to root formation, but they do not form part of a protein molecule

46. Yes Nitrate ions are combined with the carbohydrate molecules produced during photosynthesis, and form amino acids and proteins

47. No Magnesium ions are needed for forming chlorophyll but not for forming proteins

48. Question 10 Diffusion of oxygen in air takes place as a result of… (a) convection currents(b) air movements (d) changes in temperature (c) random movement of molecules Question 11

49. No Convection currents would move the air as a whole. It would not specifically affect any one gas in the air

50. No Air movements would affect all atmospheric gases in the same way

51. Yes Small random movements of oxygen molecules results in their moving, eventually, from a place where the molecules are more abundant to places where they are scarcer, until they are evenly distributed

52. No Changes in temperature affect all the atmospheric gases. A rise in temperature may speed up diffusion but not specifically of oxygen

53. Question 11 In osmosis, water will diffuse through a partially permeable membrane… (a) from water to a concentrated solution (b) from a concentrated to a dilute solution(c) from a dilute solution to a concentrated solution (d) from a dilute solution to a more dilute solution

54. Yes

55. No The water movement in osmosis is from the dilute solution to the concentrated solution

56. Yes

57. No In osmosis the diffusion of water between solutions is always from the more dilute solution to the less dilute (i.e. more concentrated) solution

58. End of questions End show Back to start