47. Which of the following mechanisms is essential for animal navigation?
(A) a time keeping mechanism
(B) a color recognition mechanism
(C) a scent recognition mechanism
(D) a sound discrimination mechanism
(E) a touch discrimination mechanism

43. Which of the following is NOT true about estuaries? (A) Estuaries are often bordered by mudflats and salt marshes. (B) Estuaries contain waters of varying salinity. (C) Estuaries support a variety of animal life that humans consume. (D) Estuaries usually contain no or few producers. (E) Estuaries support many semiaquatic species.

44. Carrying capacity is (A) seldom reached by marine producers and consumers because of the vast resources of the ocean. (B) the maximum population size that a particular environment can support. (C) fixed for most species over most of their range most of the time. (D) determined by density and dispersion data. (E) the term used to describe the stress a population undergoes due to limited resources.

45. The emergence of 14 species of Galápagos finches from a common ancestor that finds itself in a new environment is called (A) adaptive radiation. (B) jumping selection. (C) disruptive selection. (D) sympatric speciation. (E) hybridization.

46. The life history strategy of an k-selected species is to (A) take advantage of human activity, such as clearing woodlots. (B) allocate energy to their own survival and to the survival of their descendants. (C) produce thousands of eggs. (D) become prey. (E) reproduce at early age.

48. The sexually mature organism retains traits of the juvenile stage of the organism’s ancestor. This is called_____. (A) metamorphosis (B) pesudomorphosis (C) paedomorphosis (D) premorphosis (E) adultery

49. Which of the following statements regarding balancing selection is FALSE? (A) The balancing selection maintains genetic diversity in a population. (B) The balancing selection can create a balanced polymorphism. (C) Homozygote advantage is usually favored by the balancing selection. (D) The balancing selection is a type of natural selection which does not always cause the elimination of weaker alleles. (E) The balancing selection can occur through negative frequency-dependent selection.

50. Isolated populations will lose a percentage of their original diversity over time, approximately at the rate of 1/(2N) per generation, where N= population size. After 20 generations, the original population of 500 will lose ___ of its original genetic variation. (A) 20% (B) 2% (C) 4% (D) 8% (E) 16%.

 51. Which of the following statements about umbrella species is correct? (A) Umbrella species are species whose habitat requirements are critical to a certain small area. (B) The Northern spotted owl (Strix occidentialis) is considered to be an important umbrella species. (C) The gopher tortoises (Gopherus polyphemus) is considered to be an important umbrella species. (D) Umbrella species must be attractive and more readily engendered support from the public for their conservation. (E) Formosan macaques are considered to be an important umbrella species in Taiwan.

52. In present populations of Taiwan Hwa-Mei (Leucodioptron taewanum) in Taiwan, genetic diversity has been (A) lost through mutation and restored by natural selection. (B) lost through stabilizing selection and restored by balancing selection. (C) lost through directional selection and restored by balancing selection. (D) lost through hybridization and restored by natural selection. (E) lost through artificial selection and restored by natural selection.

53. The Morakot typhoon inflicted catastrophic damages on rivers and wiped out entire population of fishes in the river. This is an example of (A) a density-dependent effect. (B) the effects of abiotic factors. (C) the interaction between density-dependent and abiotic factors. (D) founder effect. (E) dispersal effect.