32. Which of the following is an example of a commensalism?
(A) fungi residing in plant roots, such as endomycorrhizae
(B) rancher ants that protect aphids in exchange for sugar-rich honeydew
(C) bacteria fixing nitrogen in plants
(D) insects pollinate flowers
(E) cattle egrets eating insects stirred up by grazing bison

28. Compare with Monocots and Eudicots, which of the following statements is FALSE? (A) A seed of Monocots has one cotyledon; that of Eudicots has two. (B) Leaf vein of Monocots is usually parallel, but that of Eudicots is usually netlike. (C) Vascular tissue of stems in Monocots is scattered, but that of Eudicots is usually arranged in ring. (D) Pollen grain of Monocots has one opening; that of Eudicots has three openings. (E) Floral organs usually in multiple of four in Monocots, but three in Eudicots.

29. Which structure is found in angiosperms but NOT gymnosperms? (A) fruit (B) spores (C) seeds (D) ovule (E) a tube that grows from the pollen to deliver sperm

30. The heterokaryotic phase of a fungal life cycle is ______. (A) a stage in which the hyphae contain only one type of haploid nucleus (B) a stage in which hyphae contain two, genetically different, haploid nuclei (C) a stage in which hyphae contain two, genetically different, diploid nuclei (D) a stage that is diploid but functions as a gametophyte (like the body of an animal) (E) a triploid stage formed by the fusion of a diploid nucleus with the haploid nucleus of a compatible hypha

31. Exercise and emergency reactions include ______. (A) decreased activity in the sympathetic, and increased activity in the parasympathetic divisions (B) increased activity in all parts of the peripheral nervous system (C) increased activity in the sympathetic, and decreased activity in the parasympathetic divisions (D) increased activity in the enteric nervous system (E) reduced heart rate and blood pressure

33. Which of the following is a greenhouse gas? (A) water vapor (B) molecular oxygen (C) molecular nitrogen (D) argon (E) carbon monoxide

34. In the figure below, which of the following survivorship curves most applies to humans living in developed countries? (A) curve A (B) curve B (C) curve C (D) curve D (E) curve E

35. _____ is formed in ______ during embryonic development. Which of the following statements is FALSE? (A) Dorsal lip, frog (B) Primitive streak, sea urchin (C) Primitive streak, chick (D) Epiblast, chick (E) Epiblast, human

36. Which of the following statements about fruit fly is FALSE? (A) Spermatheca can be used to store sperm in male fly. (B) Defective expression of Hox genes suppresses the embryonic development. (C) The courtship behaviors include orienting, tapping and singing. (D) Toll receptor leads to synthesis of antimicrobial peptides against fungi. (E) Drosophila melanogaster has a diploid number of 8.

37. Which insect is classified incorrectly? (A) mosquitoes - Diptera (B) butterflies - Lepidoptera (C) bees - Lepidoptera (D) flies - Diptera (E) grasshoppers - Orthoptera

38. Which of the following statements about the reproductive cycles of human female is FALSE? (A) Low level of estradiol inhibits the secretion of pituitary gonadotropins. (B) High level of estradiol stimulates the secretion of pituitary gonadotropins. (C) High level of estradiol and progesterone stimulates the secretion of pituitary gonadotropins. (D) High level of LH (luteinizing hormone) stimulates ovulation. (E) High level of estradiol and progesterone stimulates the maintenance of endometrium.