47. Transport in plants include all of the following except
(A) absorption of water and minerals from the soil by cells of a root.
(B) that transpiration creates a force within leaves that pulls xylem sap upward.
(C) leaves exchange gases through stomata, taking in the CO₂ that provides carbon for photosynthesis and expelling O₂.
(D) active transport of sugar from one sieve-tube to the next.
(E) that potassium is uptaken by guard cells during stomatal opening.

43. Among the invertebrates, arthropods are unique in possessing (A) a notochord. (B) open circulation. (C) segmented bodies. (D) ventral nerve cords. (E) jointed appendages.

44. Important terrestrial adaptations that evolved exclusively in seed plants include all of the following except (A) pollination by wind or animal instead of fertilization by swimming sperm. (B) transport of water through vascular tissue. (C) retention of the gametophyte plant within the sporophyte. (D) dispersal of new plants by seed. (E) protection and nourishment of the embryo within the seed.

45. Which of the following enzymes has the lowest pH optimum? (A) lipase (B) pepsin (C) trypsin (D)sucrase (E) amylase

46. Which of the following definitions of “Animal” is not true? (A) Animals are multicellular eukaryotes distinguished by a specific type of heterotrophy called ingestion. (B) In most animals, cells are successively organized into tissues, organs, and organ systems. (C) Animal cells lack cell walls and store carbohydrate reserves as starch. (D) Animal reproduction is primarily sexual; asexual budding or regeneration occurs in some species. (E) Muscles and nerves, which control active behavior, are unique to animals.

48. A hummingbird with a beak that is too short to pollinate a flower is an example of (A) behavioral isolation. (B) temporal isolation. (C) gametic isolation. (D) mechanical isolation. (E) postzygotic isolation.

49. Antibodies of the different classes IgM, IgG, IgA, IgD and IgE differ from each other in (A) the way they are produced. (B) the type of cell that produces them. (C) the way they interact with the antigen. (D) the antigenic determinants that they recognize. (E) the number of carbohydrate subunits they have.

50. Which of the following signal transduction molecules is not bound to the plasma membrane? (A) G proteins (B) Phospholipase C (C) Adenylyl cyclase (D) Second messengers (E) Receptors for peptide hormones

51. Reabsorption of useful components of glomerular filtrate occurs in (A) Bowman’s capsule. (B) proximal convoluted tubule. (C) distal convoluted tubule. (D) collecting duct. (E) gall bladder.

52. Which of the following is true? (A) The leaves of both angiosperms and gymnosperms are covered by a waxy cuticle that helps to protect the leaves from desiccation. (B) Both angiosperms and gymnosperms produce ovules in a specialized structure called an ovary. (C) “Double fertilization” to produce a fertilized egg and a triploid endosperm is characteristic of both angiosperms and gymnosperms. (D) The gametophyte is the dominant generation in both the angiosperms and gymnosperms. (E) All of the statements are true.

53. Two animal species live in the same biome but on different continents. Although these two are not closely related, they may appear quite similar as a result of (A) gene flow. (B) parallel evolution. (C) convergent evolution. (D) divergent evolution. (E) allopatric speciation.