38. Phenylketonuria (PKU) is due to a recessive allele. Given 1 PKU occurrence per 25 births, what is the frequency of individuals with the heterozygous phenotype if the population is in Hardy-Weinberg equilibrium?
(A) 0.2
(B) 0.32
(C) 0.64
(D) 0.8
(E) 0.96

34. Which of the following vitamins involves primarily in transamination reactions of amino acid metabolism? (A) Vitamin C (B) Vitamin E (C) Vitamin B6 (D) Vitamin B12 (E) Vitamin A

35. Martin and Mary have free earlobes, but their son Mark does not. If Martin and Mary have two more children, what is the probability that both will have attached earlobes? (A) 1/4 (B) 3/4 (C) 1/16 (D) 9/16 (E) 3/16

36. Which of these statements best describes stem cells? (A) Adult stem cells but not embryonic stem cells are immortal in lab culture. (B) Only embryonic stem cells are found in every tissue of the adult body. (C) Embryonic stem cells and induced pluripotent stem cells give rise to all the different types of cells in the organism. (D) Stem cells can be isolated from the inner cell mass of blastocytes, bone marrow, and amniotic fluid, but not from adipose tissues. (E) Cancer stem cells possess characteristics associated with normal stem cells.

37. Which order is correct according to the number of genes from big to small in the following organisms? 1. E. coli 2. Rice 3. Human sperm 4. D. melanogaster (Fruit fly) 5. Saccharomyces cerevisiae (yeast) (A) 23451 (B) 24351 (C) 34251 (D) 32415 (E) 34521

39. Which of these statements best describes speciation? (A) Populations separated by a geographic barrier are known as sympatric populations. (B) Geographic isolation necessarily leads to new species. (C) For allopatric speciation to occur, changes in the gene pool must produce reproductive isolation. (D) In allopatric speciation, reproductive isolation develops and new species arises without geographic separation. (E) A small population is less likely to have its gene pool changed by genetic drift and natural selection.

40. ______ clinical trial tests on the target human population, and ______ clinical trial maximize the number of test subjects and include human subjects of both sexes, different ethnic groups, and those who have health problems besides the one that the drug is intended to benefit. (A) Phase I; phase II (B) Phase I; phase III (C) Phase II; phase III (D) Phase II; phase IV (E) Phase III; phase IV

41. Which of the following normal ranges for measurements of some fasting blood values is FALSE? (A) Glucose: 75-110 mg/dL (B) Arterial blood pH: 7.00-7.45 (C) Protein: 6.5-8 g/dL (D) Cholesterol: less than 200 mg/dL (E) Sodium: 135-145 mM

42. Which of these statements about a secondary immune response is FALSE? (A) Antibodies of the IgE class are produced. (B) Antibodies are made quickly and in great amounts. (C) Antibody production lasts longer than in a primary response. (D) Lymphocyte clones are believed to develop. (E) It provides active immunity against the specific pathogens.

43. Which of these statements about muscle contraction is FALSE? (A) Ca2+ is required for all muscle contraction. (B) Troponin is present in skeletal muscles and smooth muscles. (C) When a skeletal muscle shortens during contraction, the H band and sarcomere shorten. (D) Skeletal muscles but not cardiac muscles require neural stimulation to contract. (E) The sarcoplasmic reticulum and transverse tubules are well-developed in skeletal muscles and poorly developed in smooth muscles. 

44. What is the correct sequence of events involving cyclic AMP as a second messenger of glucagon hormone?  1. The stimulation of the activity of adenylate cyclase.  2. The activation of G-proteins. 3. The conversion of ATP to cyclic AMP.  4. The activation of of protein kinase A.  5. The stimulation of lipid mobilization.  6. An increase in the activity of hormone-sensitive lipase. (A) 213645 (B) 213456 (C) 214356 (D) 213465 (E) 214365