18. Contact of a sea urchin egg with signal molecules on sperm causes the egg to undergo a brief _.
(A) mitosis
(B) membrane depolarization
(C) spermatogenesis
(D) acrosomal reaction
(E) endocytosis

14. Many endotherms use a countercurrent exchange system to conserve heat. How does this function? (A) Heat is transferred from arteries to veins against a thermal gradient. (B) Heat is transferred from veins to arteries against a thermal gradient. (C) Heat is transferred from arteries to veins along a thermal gradient. (D) Heat is transferred from veins to arteries along a thermal gradient. (E) Heat is transferred either from-veins-to-arteries or from-arteries-to-veins, as long as it is along a thermal gradient.

15. After surgical removal of the gallbladder, a person might need to limit his or her dietary intake of (A) protein (B) fat (C) sugar (D) starch (E) cellulose

16. Which of the following respiratory system is not closely associated with the blood supply? (A) the lung of a vertebrate (B) the gills of a fish (C) the tracheal system of an insect (D) the skin of an earthworm (E) none of above

17. Which of the following should be the same in identical twins? (A) the set of antibodies produced (B) the set of MHC molecules produced (C) the set of T cell antigen receptors produced (D) the set of fingerprints for each person (E) the set of immune cells eliminated as self-reactive

19. Circannual rhythms in birds are influenced by _. (A) periods of food availability (B) lunar cycles (C) magnetic fields (D) periods of daylight and darkness (E) moon lights

20. Suppose researchers marked 800 turtles and later were able to trap a total of 300 individuals in that population, of which 150 were marked. What is the estimate for total population size? (A) 200 (B) 400 (C) 1250 (D) 1600 (E) 2100

1. Which is NOT the digestive enzymes in the small intestine (A) Bile salts (B) Lactase (C) Dipeptidase (D) Pancreatic amylase (E) Cytochrome c oxidase

2. Characteristic of simple epithelium is that they (A) are arranged indiscriminately (B) continue to divide and help in organ function (C) make a definite layer (D) None of above

3. Which description is NOT correct about Vitamin D (A) Diet obtaining from egg yolk (B) Deficiency resulting in bone deformities and softening (C) Liver damage and anemia while deficiency (D) Aids in absorption and use of calcium and phosphorus (E) Important for cardiovascular functionality

4. Which is NOT the risk factor for high blood cholesterol and high blood pressure (A) Fatty diet (B) Lack of exercise (C) Being male (D) Aging (E) High protein consuming