57. Mammalian Toll-like receptors (TLRs) recognize macromolecules present on certain groups of pathogens. Which of the following is most likely to be recognized by TLR that defends against certain viruses?
(A) lipopolysaccharides
(B) double-stranded peptide
(C) double-stranded RNA
(D) gylcoproteins
(E) phosphopeptides

53. When we refer to a plant as a “short-day plant”, we mean that _____. (A) the plant flowers in winter (B) the plant flowers when day is shorter than 12 hours (C) the plant flowers only in the equator area (D) the plant flowers when the night is longer than its own critical night length (E) both A and D 

54. Which of the following statements regarding photosynthesis is FALSE? (A) The principal electron carrier in photosynthesis is NADPH; the principal electron carrier in respiration is NADH. (B) The light reactions occur in the stroma, while the Calvin cycle occurs in the thylakoid membranes. (C) The light reactions of photosynthesis can produce ATP, NADPH and O2. (D) Sunlight is a type of electromagnetic energy. (E) Chlorophyll a reflects green light.

55. Which of the following statements about gas exchange is FALSE? (A) Breathing control centers are located in parts of the brain called the cerebellum and medulla oblongata. (B) The control center regulates breathing rate in response to changes in the CO2 level of the blood. (C) Gills are unsuitable for animals living on land because the large surface area of gills would allow dehydration of the animal. (D) Unlike the tracheal system of insects, vertebrate lungs are restricted to one location in the body. (E) Medullary breathing centers directly sense and respond to blood pH and CO2 concentration.

56. Which of the following statements is FALSE? (A) Speciation, or the formation of new species, is the bridge between microevolution and macroevolution. (B) The likelihood of allopatric speciation increases when a splinter population is small and isolated from the broader range of the species. (C) Speciation without geographic isolation is called allopatric speciation. (D) Organisms carry more than two complete sets of chromosomes in are called as polyploid. (E) Most polyploid species arise from the hybridization of two parent species and subsequent chromosome duplications.

58. Hemoglobin is responsible for transporting oxygen from lung to tissues. Bohr shift is one of the most important properties of hemoglobin. Which of the following is NOT true about Bohr shift? (A) Additional oxygen is bound by hemoglobin in lung when pH decreases. (B) Additional oxygen is released from hemoglobin at a lower pH. (C) Carbon dioxide is involved in Bohr shift. (D) Bohr shift helps tissues to obtain more oxygen in exercise. (E) None of the above.

59. Which of the following can maintain gene expression from lac operon? (A) High level of glucose from the breakdown of lactose (B) Lactose must binds to the operator (C) High level of cAMP in the presence of lactose (D) Repressor must binds to operator (E) Stop producing repressor

60. Animals release their nitrogenous waste in different forms. Which of the following statements are true ? ① Urea is excreted by many marine fishes. ② Ammonia is so toxic that it is rarely excreted as nitrogenous waste by any animals. ③ The animals in dry environment could excrete uric acid. ④ The form of nitrogenous waste is often an adaptation to animal habitats. (A)① ② ③ ④ (B) ① ② (C) ① ②④ (D) ②④ (E) ①③ ④

61. Diversity of antibodies arises from which of the following? (A) Assortment of V, D, J gene segments (B) Junctional variation upon V-D or D-J joining (C) Somatic mutation (D) Assortment of heavy and light chain genes (E) All of the above

62. Genes A and B are linked on the same chromosome with recombination frequency of 20%. What will be the frequency of offspring with recessive phenotype from a cross between individuals with AB/ab and Ab/aB genotypes? (A) 20% (B) 10% (C) 6% (D) 4% (E) 2%

63. How does the occurrence of self-fertilization relative to cross-fertilization affect the fixation of an advantageous and recessive allele that newly arose in population by mutation? (A) The relative occurrence of self-fertilization does not affect the fixation of the allele. (B) The relative occurrence of self-fertilization affects the fixation of the allele only when the population is very small. (C) The allele will be fixed more quickly when the occurrence of self-fertilization is higher. (D) The allele will be fixed more quickly when the occurrence of self-fertilization is lower. (E) The allele will be fixed more quickly when the occurrence of cross-fertilization is higher.