9. The large surface area in the gut directly facilitates_____.
(A) secretion
(B) absorption
(C) filtration
(D) temperature regulation

5. What is the only type of chemical signal that does not alter the physiology of the animal producing that signal? (A) neural (B) paracrine (C) neuroendocrine (D) pheromones

6. Innate immunity _____ .(A) is activated immediately upon infection (B) depends on an infected animal's previous exposure to the same pathogen (C) is based on recognition of antigens that are specific to different pathogens (D) is found only in vertebrate animals

7. Select the pathway that would lead to the activation of cytotoxic T cells. (A) B cell contact antigen → helper T cell is activated → clonal selection occurs (B) body cell becomes infected with a virus → new viral proteins appear → class I MHC molecule-antigen complex displayed on cell surface (C) complement is secreted → B cell contacts antigen → helper T cell activated → cytokines released (D) cytotoxic T cells → class II MHC molecule-antigen complex displayed → cytokines released → cell lysis

8. You cut your finger, and after putting pressure on the wound for several minutes, you notice that it is still bleeding profusely. What may be the problem? (A) Platelets are not functioning properly, or there are too few to be effective. (B) Mast cells are not releasing their chemical messengers. (C) There are too many antigens to allow clotting. (D) Hemoglobin levels are too high to allow clotting.

10. The motor (somatic nervous) system can alter the activities of its targets, the skeletal muscle fibers, because _____.(A) it is electrically coupled by gap junctions to the muscles (B) its signals bind to receptor proteins on the muscles (C) its signals reach the muscles via the blood (D) it is connected to the internal neural network of the muscles

11. Imagine that a woman is in the final week of her pregnancy. Her doctor gives her an injection of oxytocin. The likely result of this is that the pregnant woman would _____.(A) stop secreting prostaglandins from the placenta (B) undergo vigorous contractions of her uterine muscles (C) increase the synthesis and secretion of progesterone (D) be prevented from lactation

12. The force driving simple diffusion is _____, while the energy source for active transport is _____. (A) the concentration gradient； ADP (B) the concentration gradient； ATP (C) transmembrane pumps； electron transport (D) phosphorylated protein carriers； ATP

複選題13. Why is ATP an important molecule in metabolism? (A) Its hydrolysis provides an input of free energy for exergonic reactions. (B) It provides energy coupling between exergonic and endergonic reactions. (C) Its terminal phosphate group contains a strong covalent bond that, when hydrolyzed, releases free energy. (D) Its terminal phosphate bond has higher energy than the other two phosphate bonds.

14. In liver cells, the inner mitochondrial membranes are about five times the area of the outer mitochondrial membranes. What purpose must this serve? (A) It allows for an increased rate of glycolysis. (B) It allows for an increased rate of the citric acid cycle. (C) It increases the surface for oxidative phosphorylation. (D) It increases the surface for substrate-level phosphorylation.

15. The beginning of anaphase is indicated by which of the following? (A) Chromatids lose their kinetochores. (B) Cohesin attaches the sister chromatids to each other. (C) Cohesin is cleaved enzymatically. (D) Spindle microtubules begin to polymerize.