31. Based on the biological species concept, reproductive isolation is a key factor of speciation. Which of the following is NOT a “prezygotic reproductive barrier”?
(A) Habitat isolation
(B) Mechanical isolation
(C) Hybrid breakdown
(D) Behavioral isolation
(E) Temporal isolation

27. In aerobic state, the reaction of glycolysis (one molecule of glucose) produces________. (A) two molecules of pyruvate, four molecules of ATP, and two molecules NADH miRNAs can block the translation of mRNA (B) two molecules of pyruvate, two molecules of ATP, and four molecules NADH (C) two molecules of pyruvate, two molecules of ATP, and three molecules NAD+ (D) two molecules of pyruvate, two molecules of ATP, and two molecules NADH (E) two molecules of pyruvate, two molecules of ATP, and two molecules NAD+

28. Spike (S) is a glycoprotein found on the surface of coronaviruses. S protein has 1273 residues in SARS-CoV-2 and has a molecular weight of 180–200 kDa. Based on the above information, we know that________. (A) the SARS-CoV-2 has a genome of 29,881 bp in length (B) the expressed S protein from E. coli would have a molecular weight around 140 kDa (C) S protein is a dimmer (D) S protein binds to the host cell by recognizing the receptor ACE2 (E) S protein plays a key role in cell membrane fusion process

29. Which of the following pairs about the accumulated molecules and metabolic disorder is NOT correct? (A) Homogentisate - Alkaptonuria (B) Tyrosine - Phenylketouria (C) Homocysteine - Homocystinuria (D) Branched-chain α-keto acids - Maple syrup urine disease (E) Uric acid - Gout

30. The following statements about DNA replication is E. coli are correct except: (A) Both leading strand and lagging strand require primer. (B) DNA polymerase adds a new nucleotide to the free 3’OH of the existing nucleic acid. (C) The principal replication enzyme is DNA polymerase I. (D) It also has a 3’5’ exonuclease activity. (E) It is a processive enzyme.

32. The virus causes COVID-19 disease. This virus is ________. (A) double-strand DNA virus (B) single-strand RNA virus (C) single-strand DNA virus (D) similar to λ phage (E) naked RNA virus

33. Which of the following creatures will be the best outgroup if you are reconstructing a phylogenetic tree of cats using cladistics? (A) domestic cats (B) leopards (C) lions (D) tigers (E) wolves

34. Which of the following is the best description about CRISPR? (A) CRISPR is directed to its target gene by a guide DNA molecule. (B) CRISPR contains nuclease to destroy target RNA. (C) CRISPR is not acquired but is preexisted in bacteria. (D) CRISPR can be applied to knockout target gene. (E) All of the above are correct.

35. Which of the following does NOT match with its function? (A) Chlorophyll a: Component of P700 reaction center (B) ATP synthase: Chemiosmotic phosphorylation (C) Cyclic electron transport: Electron flow from water to NADPH (D) RuBP: Conjugates carbon dioxide (E) Carotenoids: Absorption of excess light

36. Which of the following is TRUE? (A) The contents of the phloem are under pressure, and the contents of the xylem are under tension. (B) Sieve tube members are dead cells. (C) Vessel element protoplasm is unique because the vacuolar membrane disintegrates, allowing vacuolar water to mix with the cytosol. (D) Phloem sap movement is driven by the atmospheric water potential. (E) Phloem sap moves only short distances, whereas xylem sap moves long distances.

37. If a normal body cell of a plant contains 5 picograms (pg) of DNA, then that cell at the end of prophase of mitosis contains ________. (A) 2.5 picograms (B) 5 picograms (C) 10 picograms (D) 15 picograms (E) 20 picograms