21. Which of the following statements about prostaglandins is true?
(A) They are one of the types of target cells
(B) They are produced by endocrine glands.
(C) They travel throughout the body by circulating in the blood.
(D) All of the above are true.
(E) None of the above is true.

17. Alzheimer's disease in human is associated with the deficiency of (A) dopamine (B) glutamic acid (C) acetylcholine (D) gamma aminobutyric acid

18. The cells responsible for color vision in vertebrates are called (A) rod cells (B) cone cells (C) bipolar cells (D) cupula cells (E) ampullae

19. During depolarization (A) moves out of the neuron (B) moves into the neuron (C) Organic ions move out of the neuron (D) All of the above (E) None of the above

20. Two antagonistic hormones are (A) MSH and TSH (B) calcitonin and parathyroid hormone (C) ADH and GH (D) oxytocin and prolactin

22. Type I diabetes mellitus is caused by a deficiency of (A) exercise (B) glucagon (C) glucose (D) glycol (E) insulin

23. Nerve impulses are normally carried toward a neuron cell body by the neuron's (A) Synaptic cleft (B) Axon (C) Hormones (D) Dendrites

24. In sensory neurons, stimuli are received by the (A) Axons (B) Dendrites (C) Cell body (D) Myelin

25. Ovulation is caused by the hormone (A) FSH (B) Progesterone (C) Oxytocin (D) Estrogen (E) Luteinizing Hormone

26. Which of the following statements is NOT true? (A) Evolutionary theory holds that all of life has a common ancestor. (B) Cladistics involves the identification of evolutionary branches that consists of an ancestral species and all its descendants. (C) Parsimony is the search for the least complex explanation for an observed phenomenon. (D) Comparisons of molecules that evolve very fast would help to determine the phylogenetic relationships of fungi, plants and animals. (E) Phylogenies are based on homologies in fossils and living organisms.

27. Which of the following is NOT true? (A) Alpha-amanitin inhibits the activity of all three RNA polymerases of eukaryotes by interacting with a bridge helix in the enzymes. (B) Chloramphenicol blocks translation by inhibiting the peptidyl transferase activity of ribosome. (C) Cycloheximide blocks translation by interfering with the translocation step in protein synthesis. (D) Cytochalasin B inhibits cytoplasmic division by blocking the formation of contractile microfilaments. (E) None of the above.