40. What is the function of calcium ions in muscle contraction?
(A) They cause actin and myosin filaments to shorten.
(B) They make membranes permeable.
(C) They allow cross-bridges to form between actin and myosin.
(D) They increase the action potential of the fiber.
(E) They decrease the action potential of the fiber.

36. A geneticist found that a particular mutation had no effect on the polypeptide coded by a gene. This mutation probably involved. (A) deletion of one nucleotide (B) alteration of the start codon (C) insertion of one nucleotide (D) deletion of the entire gene (E) substitution of one nucleotide

37. The tendency for characteristics to be more different in sympatric populations of two species than in allopatric populations of the same two species is called (A) competitive exclusion (B) character displacement (C) niche shift (D) speciation (E) dynamic equilibrium

38. Which of the following is an INCORRECT statement about cyanobacteria ? (A) they are photoautotrophic (B) they were formerly known as blue-green algae (C) they belong to Domain Bacteria (D) some of their members produce specialized heterocysts for nitrogen fixation (E) their cells contain chioroplasts

39. Noncyclic photophosphorylation is different from cyclic photophosphorylation in that (A) noncyclic photophosphorylation produces ATP (B) cyclic photophosphorylation produces ATP (C) noncyclic photophosphorylation produces NADPH (D) cyclic photophosphorylation produces NADPH (E) noncyclic photophosphotylation includes dark reactions

41. A graduate student growing plant cells in a laboratory dish wanted to cause them to _, so the graduate student j treated them with cytokinins. I (A) enlarge (B) become dormant (C) grow roots (D) produce auxins (E) divide 量

42. Which of the following structures is incorrectly paired with its function? (A) epididymis - maturation and storage of sperm  (B) uterus — fertilization of an egg (C) seminal vesicles — add sugar and mucus to semen  (D) placenta - matemal/fetal exchange organ; progesterone producing (E) prostate gland — adds alkaline substances to semen

43. An area of habitat where a population's reproductive success exceeds mortality is (A) the results of edge effect (B) going to occur speciation very soon (C) a source habitat to the population (D) going to decrease population size (E) the effective size of the population

44. Which of the following is an INCORRECT statement about fungi? (A) they are heterotrophs (B) most of their bodies are constructed of hyphae : (C) their cell walls mainly consist of cellulose (D) they are more closely related to animals than plants (E) they serve as decomposers in communities £

45. Fermentation is essentially glycolysis plus an extra step in which pyruvic acid is reduced to form lactic acid or alcohol ; and carbon dioxide. This last step 養 (A) removes poisonous oxygen from the environment (B) extracts a bit more energy from glucose [ (C) enables the cell to recycle NAD+ (D) inactivates toxic pyruvic acid (E) enables the cell to make pyruvic acid 奪 into substances it can use [

46. A biologist isolated a gene from a human cell, attached it to a plasmid, and inserted the plasmid into a bacterium. The I； bacterium made a new protein, but it was nothing like the protein normally produced in a human cell. Why? ; (A) the bacterium had undergone transformation (B) the gene did not have sticky ends 誓 (C) the gene contained introns (D) the gene did not come from a genomic library ; (E) the biologist should have cloned the gene first ^