65. In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium. The frequency of aa individuals in the population is about 0.09. What is the frequency of individuals with Aa genotype?
(A) 0.18
(B) 0.21
(C) 0.36
(D) 0.42
(E) 0.91

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.

64. Which of the following statements regarding inheritance is FALSE? (A) “Ture-breeding” means varieties for each self-fertilization produced offspring all identical to the parent. (B) The offspring of two different varieties are called hybrids. (C) A monohybrid cross is a breeding experiment in which the parental varieties differ in some characters. (D) The hybrid offspring of an F1 cross are the F2 generation. (E) The hybrid offspring of a cross are the F1 generation.

66. Which of the following statements regarding epigenetics is FALSE? (A) The study of inherited changes in genotype, especially in gene expression caused by the changes of DNA sequence. (B) Specific epigenetic processes include imprinting, gene silencing, X chromosome inactivation, and position effect. (C) Some regulation can be associated with microRNA. (D) Some regulation can be associated with DNA methylation. (E) Some regulation can be associated with histone modification

67. The difference between bacteria and archaea is (A) Membrane-enclosed organelles are present or not. (B) Circular chromosome. (C) Streptomycin inhibits growth. (D) Both A and C. (E) All of A, B, and C.

68. Which of the following pathways best summarizes the route of a mineral that is absorbed by a plant? (A) root hair, epidermis, cortex, stele, endodermis, xylem (B) root hair, cortex, epidermis, stele, endodermis, xylem (C) root hair, cortex, epidermis, endodermis, stele, xylem (D) root hair, epidermis, cortex, endodermis, stele, xylem (E) root hair, epidermis, stele, cortex, endodermis, xylem

69. Which of these sequences correctly describes the cell cycle? (A) G1, G2, S, prophase, metaphase, anaphase, telophase (B) G1, G2, S, prophase, metaphase, telophase, anaphase (C) S, G2, prophase, metaphase, anaphase, telophase, G1 (D) G1, S, G2, metaphase, prophase, anaphase, telophase (E) G2, S, prophase, metaphase, anaphase, telophase, G1

70. Which of the following statements about immunoglobulin is FALSE? (A) IgG is the most abundant immunoglobulin in serum. (B) IgM can activate classical complement pathway. (C) IgE can induce mast cell degranulation. (D) IgG is the first immunoglobulin class produced in a primary response to an antigen. (E) IgA is the predominant immunoglobulin class in external secretions such as breast milk, saliva and tears.

71. One of the typical ratios resulting from epistatic interactions in dihybrid crosses would be (A) 9:3:3:1 (B) 1:1:1:1 (C) 9:3:4 (D) 1:2:1 (E) 3:1