31. An embryonic cell that is totipotent is one that can __________.
(A)migrate into the center of the blastula during gastrulation
(B)give rise to the entire embryo, by itself, as cleavage proceeds
(C)organize the blastula
(D)redistribute yolk from the vegetal to the animal pole of the frog embryo
(E)move mesodermal cells in the blastocoel

27. By definition, a clade is __________. (A)parsimonious (B)polyphyletic (C)monophyletic (D)paraphyletic (E)analogous

28. Which of the following is true of microevolution? (A)it is the kind of evolution that can change the relative abundance of a particular allele in a gene pool over the course of generations (B)it is evolution that influences only a small subset of the populations that comprise a species (C)it is evolution that is restricted to individual organisms (D)it is evolution that involves only tiny changes to DNA, such as point mutations, producing only small (if any) changes to phenotype (E)it is evolution that results in the origin of small numbers of new species

29. Which of the following animals uses the largest percentage of its energy budget for homeostatic regulation? (A)snake in a temperate forest (B)desert bird (C)marine jelly (an invertebrate) (D)desert insect (E)pond turtle

30. Which of the following would increase the rate of heat exchange between an animal and its environment? (A)wind blowing across the body surface (B)feathers or fur (C)countercurrent heat exchanger (D)vasoconstriction (E)ATP synthesis

32. When climbing a mountain, we can observe transitions in biological communities that are analogous to the changes _______(A)in different depths in the ocean. (B)in biomes at different latitudes. (C)in an ecosystem as it evolves over time. (D)in a community through different seasons. (E)in a composition of different atmosphere.

33. What are the most abundant animals found in the pelagic zone? (A)echinoderms (B)cnidarians (C)zooplankton (D)dinoflagellates (E)marine mammals

34. The principle of competitive exclusion states that ________(A)competition between two species always causes extinction or emigration of one species. (B)two species cannot coexist in the same habitat. (C)two species will stop reproducing until one species leaves the habitat. (D)two species that have exactly the same niche cannot coexist in a community. (E)can create the new species.

35. Food chains tend to be short because ______ (A)most producers are inedible. (B)local extinction of a species causes extinction of the other species in its food chain. (C)most of the energy in a trophic level is lost as energy passes to the next higher level. (D)only a single species of herbivore feeds on each plant species. (E)most consumers are herbivore.

36. Which of the following could qualify as a top‐down control on a grassland community? (A)effect of grazing by bison on plant species diversity (B)influence of soil nutrients on the abundance of grasses versus wildflowers (C)influence of temperature on competition among plants (D)limitation of plant biomass by rainfall amount (E)limitation of water supply during drought season

37. What happens first when a phage infects a bacterial cell and is going to enter a lysogenic cycle? (A)when the bacterial chromosome replicates, viral DNA is also replicated (B)linear DNA circularizes (C)viral DNA becomes inserted into the bacterial chromosome (D)all bacterial descendants will carry the viral genes (E)the host cell is lysed by the invasion