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

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.

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

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.

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

72. In the absence of recombination, what ratio of phenotypes is expected in the progeny of the cross aB/Ab x AB/ab? (A) 3 A-B- : 1 aabb (B) 1 aaB- : 2 A-B- : 1A-bb(C) 9 A-B- : 3 A-bb : 3 aaB- : 1 aabb (D) 1 A-B- : 1 A-bb : 1 aaB- : 1 aabb (E) 1 aB : 1 Ab : 1 AB : 1 ab

73. Diabetes insipidus is a disorder marked by production of abnormally large in volume and very dilute urine. It can cause severe dehydration. The mechanism(s) attributing the disorder can be (A) mutations that prevent ADH production (B) mutations that inactivate aquaporin (C) mutations that inactivate insulin receptor (D) both A and B (E) all of the A, B, and C

74. Which of the following statements is (are) positive feedback? (A) The hormones stimulate uterus contraction when child-birth occurs in mammals. (B) A nursing infant's sucking increases the secretion of a milk-releasing hormone in the mother. (C) An increase in calcium concentration increases the secretion of a hormone that stores calcium in bone. (D) Both A and B. (E) All of A, B, and C.