Nov 2007 O Level Paper 1

1. D

2. C

3. A

4. D

5. C [The question is indirectly asking which graph shows the effect of temperature on the rate of photosynthesis. As enzymes are involved in photosynthesis, temperature does affect the rate of photosynthesis, as shown in Graph C.]

6. A [Similarly, rate of evolution (release) of oxygen by plants is used to measure the rate of photosynthesis. Thus as the rate of evolution of oxygen increases, the rate of photosynthesis increases.]

7. C

8. B [Note: For a structured question, please indicate that there will be more efficient absorption of digested food, as absorption can still occur without the villi, but villi helps to increase surface area to volume ratio and thus increasing the efficiency of absorption.]

9. C [3-pancreas, 5-liver, note:4-gall bladder simply stores bile.]

10. B [hepatic portal vein transport blood from small intestines (ileum) to the liver.]

11. B [Water potential in Cell W has to be the lowest to allow water to enter into the root cells from the surrounding soil (from Z --> Y --> X --> W).]

12. D [Note: phloem transports sucrose.]

13. B [antibody formation and phagocytosis are functions of the WBCs, and WBCs are responsible for tissue rejection.]

14. B [The most obvious one first, No.3 has to be pulmonary vein as it receives oxygenated blood from the heart and brings it to the left atrium. Hepatic vein not obvious, but renal vein is obviously no.1 as much of the urea is already used in the formation of urine.]

15. A [Plasma refers to the liquid portion of blood, thus its water potential has to decrease to allow water to re-enter the capillary. Blood pressure also has to decrease as blood flows from a region of higher pressure to lower pressure, thus with a lower pressure, blood (with water) can re-enter the capillary.]

16. C [A is definitely wrong as blood from the intestines will not flow to the heart. B is wrong as right ventricle and head should not be connected. Right ventricle should be connected to lungs only. D is wrong as the left atrium and lungs should be connected as oxygenated blood from lungs will return to the left atrium of the heart.]

17. D

18. B

19. B [It has the thinnest alveoli wall and it has the blood capillary closest to the wall.]

20. D [Volume of liquid in Y has to be much more than in Z. Y (renal vein) is carrying blood while Z (ureter) is carrying urine. Logically, the volume of urine has to be much lesser than that of blood. Also only the excess water of the body is found in urine. As for X(renal artery) and Y, a small amount of water (which is those in excess) is excreted out of the body as urine, thus X will have a higher volume of liquid than Y.]

21. C

22. D

23. C [Lens changes from seeing a distant object, to a very near object, to a not-so-distant object.]

24. B [As it has less cilia to sweep away the mucus.]

25.

26.

27. Not tested for MYE

28. Not tested for MYE

29. Not tested for MYE

30. Not tested for MYE

31.

32. A

33. D [must be from anther to stigma.]

34. B

35. D [Sperms and male sex hormones will still be produced, but it cannot be transported beyond the point at which the sperm ducts are cut.]

36. Not tested for MYE

37. Not tested for MYE

38. Not tested for MYE

39. Not tested for MYE

40. Not tested for MYE