39. How do T cell receptor recognize antigen?
(A) Antigen receptors of T cell bind to antigens on the surface of a virus.
(B) the antigen receptors on the surface of the helper T cell bind to antigen fragments complex with class-I MHC molecules on the antigen-presenting cell.
(C)accessory protein CD8 on the helper T cell surface binds to the MHC molecules, helping keep the cell-cells joined.
(D) an antigen fragment binds to an MHC molecule and then displayed to the cell surface. The combination of MHC molecule and antigen is recognized by T cell.
(E)None of the above.

35. Which one of the following statements is NOT true? (A) Fish gills use a countercurrent exchange system to increase blood flow. (B) In fish gills, more than 80% of the O2 dissolved in the water is removed as water passes over the respiratory surface. (C)In human lungs, cilia and mucus line the epithelium of the air ducts and move particles up to the pharynx. (D) Respiratory surfaces are always thin and moist. (E)All of the above.

36. Which one is secreted by cytotoxic T cells? (A) histamine (B) perforin (C)IgG (D) IL-1β (E)None of the above.

37. Which of the following is true of innate behaviors? Innate behaviors __________.(A) are only weakly influenced by genes (B) occur in invertebrates and some vertebrates but not mammals (C)are limited to invertebrate animals (D) are expressed in most individuals in a population (E)None of the above.

38. What is cell mediated immunity? (A) presence of antigen cause B cell to proliferation and differentiate into plasma cells and memory B cells. (B) effector T cells are needed to eliminate intracellular pathogens (within intracellular vesicles of cells following phagocytosis (CD4) or in the cytoplasm of infected cells (CD8) (C)occurs during thymic education, T cells that react with antigens present before birth are deleted to eliminating self-reactivity. (D) heterodimer produced by macrophages and dendritic cells. Major cytokine to induce differentiation. of CD4+ T cells into TH1 cells. (E)All of the above.

40. The major function of the colon is the absorption of _______ and _______. (A) minerals； water (B) peptides； minerals (C)water； vitamins (D) minerals； vitamins (E)peptides； vitamins

41. Which one of the following statements is NOT true? (A) Most of CO2 from respiring cells diffuses into the blood and is transported in solution in blood plasma. (B) Nitric oxide (NO) is a major inducer of vasodilation. (C)The medulla regulates the rate and depth of breathing in response to pH changes in the cerebrospinal fluid. (D) Return of blood to the heart can be enhanced by contraction of smooth muscle in venule walls and skeletal muscle contraction. (E)None of the above.

42. Which one of the following statements is not true? (A) The development of body organs of a human embryo mainly occurs in the first 3 months of pregnancy. (B) During human pregnancy, the function of mucus plugs in the cervix is to prevent a second fertilization. (C)About 24 hrs after fertilization, the zygote begins to divide by mitosis without changes in embryo size. (D) In human pregnancy, the mother's blood contains DNA from the fetus. (E)All of the above.

43. Sensory transduction of light/dark information in the vertebrate retina is accomplished by (A) rods and cones (B) horizontal cells (C)amacrine cells (D) ganglion cells (E)bipolar cells

44. The amnion cells of human embryos are derived from___________. (A) hypoblasts (B) epiblasts (C)trophoblasts (D) allantois (E)None of the above.

45. Signals from _______ induce cells above to become cells of neural plate. (A) archenteron (B) vegetal pole (C)yolk sac (D) notochord (E)None of the above.