26. Which of the following domains combines dimerization and DNA-binding surfaces in a long helix?
(A) homeodomain
(B) zinc finger
(C) leucine zipper
(D) helix-turn-helix
(E) acidic domain

22. Living in a group confers what advantage on an animal? (A) access to mate (B) increased ability to forage (C) protection from diseases (D) A and B (E) B and C

23. How are the action potentials of pacemaker cells spread to other cardiac cells? (A) via cardiac innervation (B) via neuromuscular junctions (C) by the sudden and instantaneous depolarization of all cardiac cells (D) via gap junctions (E) A and B

24. The percentage of the human genome that encodes proteins is approximately (A) 90 %. (B) 70 %. (C) 35 %. (D) 20 %. (E) 3 %.

25. The nuclear envelope breaks down at the end of (A) S phase. (B) G2 phase. (C) prophase. (D) metaphase. (E) anaphase.

27. Why do the kidney’s activities require large amounts of energy? (A) Filtration requires high blood pressure. (B) Tubular reabsorption involves active transport. (C) Water is removed from the urine by active transport. (D) Osmosis occurs in energized proteins in the walls of capillaries. (E) All of the above.

28. Hypophosphatemia is inherited as an X-linked dominant. A woman without hypophosphatemia and a man with hypophosphatemia have a daughter. The daughter mates with a male without hypophosphatemia. What is the expected phenotypic ratio of their offspring? (A) 3 unaffected females : 1 male with hypophosphatemia (B) 2 unaffected females : 1 unaffected male : 1 male with hypophosphatemia (C) 1 unaffected female : 1 female with hypophosphatemia : 1 unaffected male : 1 male with hypophosphatemia (D) 1 unaffected female : 1 male with hypophosphatemia (E) 1 female with hypophosphatemia : 1 unaffected male

29. Birds are like their reptile ancestors, but their bodies are highly modified for flight. Which of the following characteristics is not an adaptation for flight? (A) feathers (B) amniotic eggs (C) a short tail (D) bones with air sacs (E) endothermic metabolism

30. All of the following are reasons why gas exchange is more difficult for aquatic animals than it is for terrestrial animals except (A) water is harder to pump than air. (B) water is denser than air. (C) water contains much less O2 than air per unit volume. (D) gills have less surface area than lungs. (E) exchanging gases with water causes substantial heat loss.

31. Which of the following is an example of polygenic inheritance? (A) skin pigmentation in humans (B) pink flowers in snapdragons (C) sex linkage in humans (D) white and purple color in sweet peas (E) the ABO blood groups in humans

32. Where is the attachment site for RNA polymerase? (A) operator region (B) initiation region (C) structural gene region (D) promoter region (E) regulator region