複選題
54. Which of the following statements about bacterial replication fork is FALSE?
(A) Helicase breaks and unwinds parental DNA.
(B) Primase synthesizes DNA primers.
(C) DNA polymerase III synthesizes leading strand.
(D) DNA polymerase I removes the primers.
(E) DNA ligase joins the Okazaki fragments.

50. All of the enzymes catalyze reactions to produce NADH , FADH2 or ATP in citric acid cycle, except ______. (A) isocitrate dehydrogenase (B) α-ketoglutarate dehydrogenase (C) succinyl-CoA synthetase (D) succinate dehydrogenase (E) citrate synthetase

51. Which of the following molecule does NOT participate in oxidative phosphorylation? (A) proton (B) Ca2+ (C) ubiquinone (Q) (D) cytochrome c (cyt c) (E) ADP

52. Which of the following statements about cell cycle is FALSE? (A) Cyclin is degraded during G1. (B) Synthesis of cyclin begins in S phase. (C) Cyclin combines with Cdk to produce maturation-promoting factor (MPF). (D) MPF promotes mitosis by phosphorylating various proteins. (E) MPF’s activity peaks during prophase of M phase.

53. Which of the following statements about inherited disorders is FALSE? (A) Cystic fibrosis, a recessive disease, is caused by the defect of Cl- transporter. (B) Tay-Sachs disease, a dominate disease, is caused by the defect in mitochondria. (C) Phenylketonuria, a recessive disease, is caused by inability to metabolized phenylalanine. (D) Huntingon’s disease, a dominate disease, is a neuron degenerative disease. (E) Sickle-cell disease caused by T to A substitution results in defect of hemoglobin.

55. Which of the following statements about the molecules of appetite regulation is FALSE? (A) Hormone ghrelin is secreted by stomach to trigger feelings of hunger. (B) Hormone insulin is secreted by pancreas to suppress appetite by brain. (C) Hormone leptin is secreted by adipose to suppress appetite. (D) Hormone PYY is secreted by small intestine to suppress appetite. (E) Hormone syndecan is secreted by hypothalamus to trigger appetite.

56. What is the order of the control of heart rhythm? 1. Signals are delayed at AV node. 2. Bundle branches pass signals to heart apex. 3. Signals from SA node spread. 4. Signals spread throughout ventricles. (A) 3 → 4 → 2 → 1 (B) 4 → 1 → 3 → 2 (C) 3 → 1 → 2 → 4 (D) 2 → 1 → 4 → 3 (E) 2 → 3 → 4 → 1

57. What is the order of the nephron? 1. Thick segment of ascending limb. 2. Distal tubule. 3. Descending limb. 4. Glomerulus. 5. Thin segment of ascending limb. 6. Collecting duct. 7. Proximal tubule. (A) 4 → 2 → 3 → 5 → 1 → 7 → 6 (B) 4 → 7 → 3 → 5 → 1 → 2 → 6 (C) 4 → 2 → 3 → 1 → 5 → 7 → 6 (D) 4 → 7 → 5 → 1 → 3 → 2 → 6 (E) 4 → 2 → 7 → 1 → 5 → 3 → 6

58. Which of the following statements about the regulation of skeletal muscle contraction is FALSE? (A) Acetylcholine releases and triggers an action potential in muscle fiber. (B) Action potential is propagated along plasma membrane and down T tubules. (C) Action potential triggers Ca2+ release from sarcoplasmic reticulum (SR). (D) Ca2+ bind to tropomyosin and release myosin-binding sites to initiate muscle contraction. (E) Amyotrophic lateral sclerosis (ALS) is a disease of muscle fibers atrophy caused by motor neuron degeneration.

59. Which of the following statements about skeleton is FALSE? (A) Nematodes use hydrostatic skeleton to move. (B) The exoskeletons of insect contain chitin. (C) The osteoblasts are bone-building cells. (D) The osteoclasts are bone-resorbing cells. (E) The joint between the head of ulna and the humerus is a pivot joint.

60. Which of the following statements about plant hormones is FALSE? (A) Auxin (IAA) is produced by shoot apical meristems to stimulate stem elongation. (B) Cytokinins are synthesized in roots to regulate cell division. (C) Gibberellins (GA) are produced by meristems of apical buds to stimulate pollen development. (D) Ethylene can be produced by most parts of the plant to promote ripening of fruits. (E) Jasmonates are derived from cartenoid regulate floral development. Ⅱ.