INTERACTIVE MULTIPLE CHOICE QUESTIONS Test 2

1. INTERACTIVE MULTIPLE CHOICE QUESTIONS Test 2 The answers are provided, but so also are explanations of why the alternatives are unsatisfactory

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. Question 1 (a) all black (b) 6 black and 6 brown X (c) 4 black and 8 brown (d) 8 black and 4 brown Question 2 A male heterozygous black mouse (Bb) is mated with a female heterozygous black mouse (Bb) and the litter consists of 12 pups. B is the allele for the black colour. The allele for brown colour is b. The dominant allele is B . Which of these ratios is closest to the expected ratio for the distribution of colour among the offspring?

4. gametes B b B BB Bb b Bb bb Not very close From the Punnett square you can see that the expected ratio is 3 black (BB or Bb) to 1 brown (bb) These are only the chance combinations. It would be possible to produce 12 black pups, since ‘black’ is the dominant allele but this is not close to the expected ratio

5. gametes B b B BB Bb b Bb bb Not very close From the Punnett square you can see that the expected ratio is 3 black (BB or Bb) to 1 brown (bb) These are only the chance combinations. It would be possible to produce 6 black and 6 brown pups but this is not very close to the expected ratio of 9:3

6. gametes B b B BB Bb b Bb bb Close but …. From the Punnett square you can see that the expected ratio is 3 black (BB or Bb) to 1 brown (bb) These are only the chance combinations. A combination of 4 black to 8 brown is close to the expected ratio of 3:9 but since black is the dominant allele it seems to be the wrong way round

7. gametes B b B BB Bb b Bb bb The closest From the Punnett square you can see that the expected ratio is 3 black (BB or Bb) to 1 brown (bb) These are only the chance combinations. A combination of 8 black to 4 brown is closest to the expected ratio of 9:3 so this would be the most likely outcome

8. Question 2 (a) Carbon dioxide (b) Carbon monoxide (c) Nitrogen oxide (d) Sulphur dioxide Question 3 Which of the following gases are the cause of acid rain?

9. No Carbon dioxide does dissolve in rain to form a weak solution of carbonic acid (H2CO3) but this is normal and does not contribute to what is known as ‘acid rain’. However it is thought to be making the ocean more acid and this is a cause for concern

10. No Carbon monoxide is a poisonous gas but does not contribute to acid rain

11. Yes Oxides of nitrogen dissolve in rain water to form nitric acid which is very harmful to lakes and land plants

12. Yes Sulphur dioxide dissolves in water to form, eventually, sulphuric acid. This damages lakes and land plants

13. Question 3 (a) involves self-fertilisation (b) maintains the characteristics of the plant (c) produces variation in the offspring (d) disperses the offspring widely Question 4 Asexual reproduction in plants

14. No Self-fertilisation is one type of sexual reproduction

15. Yes Asexual reproduction does maintain the parental characteristics in all the offspring. This is particularly valuable in horticulture for retaining the desirable characteristics of a plant.

16. No Asexual reproduction does not result in variation among the offspring

17. No Asexual reproduction does not result in dispersal. Plants produced by asexual reproduction usually grow in clumps or colonies

18. Question 4 (a) A (b) B (c) AB (d) O Question 5 A mother’s blood group is A. The father’s blood group is AB. Which of the following blood groups could appear in their children?

19. Yes The mother’s genotype could be IaIa or IaIo The father’s genotype can only be IaIb Their child’s genome could therefore include IaIa, IaIo, IaIb or IbIo The first two of these would be expressed as group A because Ia is dominant to Io

20. Yes The mother’s genotype could be IaIa or IaIo The father’s genotype can only be IaIb Their child’s genome could therefore include IaIa, IaIo, IaIb or IbIo IbIo would be expressed as group B because Ib is dominant to Io

21. Yes The mother’s genotype could be IaIa or IaIo The father’s genotype can only be IaIb Their child’s genome could therefore include IaIa, IaIo, IaIb or IbIo In the the combination IaIb the alleles are codominant and would be expressed as group AB

22. No The mother’s genotype could be IaIa or IaIo The father’s genotype can only be IaIb Their child’s genome could therefore include IaIa, IaIo, IaIb or IbIo The combination IoIo could not arise

23. Question 5 (a) A genus (b) A species (c) A class (d) A family Question 6 Ranunculus bulbosus is

24. No The genus is Ranunculus. This is the genus which includes the buttercups

25. Yes The use of the binomial name indicates that Ranunculus bulbosus is a species (the bulbous buttercup).

26. No The class would be flowering plants

27. No The family would be Ranunculaceae which includes clematis, anemone, water lily as well as buttercup.

28. Question 6 (a) a response to a stimulus (b) negative phototropism (c) positive phototropism (d) positive geotropism Question 7 Sunflower seedlings with straight shoots are placed on a window sill. After a period of several hours, the growing parts of the stems have turned through 30o and are now growing towards the window. This is an example of

29. This is certainly a response (growth movement) to a stimulus (light from one side) but it is possible to be more precise

30. No Negative phototropism implies a growth movement away from the light source

31. Yes This is an example of positive phototropism, a growth movement (response) towards the light source (the stimulus)

32. No Geotropism refers to a response to gravity acting on one side of the plant.

33. Question 7 (a) Respiration (b) Photosynthesis (c) Combustion (d) Decay Question 8 Which of these processes increase the concentration of carbon dioxide in the atmosphere?

34. Yes Aerobic respiration involves the oxidation of carbohydrates with the production of carbon dioxide. For example C6H12O6 + 6O2 6CO2 + 6H2O Anaerobic respiration involves the breakdown of carbohydrates with the production of carbon dioxide and products such as alcohol or pyruvic and lactic acids. For example C6H12O6 2CO2 + 2C2H5OH alcohol

35. No Photosynthesis removes carbon dioxide from the atmosphere. 6CO2 + 6H2O C6H12O6 + 6O2 glucose

36. Yes When carbon-containing substances burn, the carbon combines with oxygen to produce carbon dioxide C + O2 CO2

37. Yes Organic compounds all contain carbon. When these decay, they release carbon dioxide. (In the absence of oxygen, decay may result in the production of methane).

38. Question 8 (a) Expansion of the vacuole (b) Division of the nucleus (c) Formation of a new cell wall (d) Increase in the amount of cytoplasm Question 9 In the growth of a plant cell, what causes the cell to increase in size?

39. Yes. The vacuole absorbs water by osmosis and pushes the cell wall outwards while it is still plastic

40. No Division of the nucleus precedes cell division but does not increase the size of cells

41. No A new cell wall is formed before cell expansion takes place, but the cell wall remains plastic till expansion is complete

42. No In the course of cell division, new cytoplasm is formed but this precedes any cell enlargement.

43. Question 9 (a) The lungs fill with air and push down the diaphragm and expand the rib cage. (b) Muscles pull the ribs upwards and outwards and cause the lungs to expand (c) The diaphragm is lowered, the ribs are pulled downwards and air is drawn into the lungs (d) The diaphragm is lowered, the rib cage is expanded and air is drawn into the lungs. Question 10 Which of these alternatives is the correct sequence of events when we breathe in?

44. No Air cannot enter the lungs unless they are first made to expand

45. Partly right The movement of the rib cage does draw air into the lungs but this is not the main force responsible

46. No. If the ribs are pulled downwards, this will reduce the volume of the thorax and counteract the effect of the diaphragm

47. Yes These two movements increase the volume of the thorax and cause air to be drawn into the lungs. The rib movements do not usually come into play except for deep breathing as in taking exercise.

48. Question 10 (a) by osmosis (b) by simple diffusion (c) against a diffusion gradient (d) down a diffusion gradient Question 11 In the process of active transport, substances move into a cell

49. No Osmosis refers only to the diffusion of water

50. No. Substances can enter the cell by diffusion but this is not active transport