76. If organisms A, B, and C belong to the same class but to different orders and if organisms D, E, and F belong to the same order but to different families, which of the following pairs of organisms would be expected to show the greatest degree of structural homology?
(A) A and B
(B) A and C
(C) B and D
(D) C and F
(E) D and F

72. Even in Darwin's time, the blending hypothesis was incompatible with observed facts. If the blending hypothesis were true, then what should one expect to observe over the course of generations? (A) Phenotypic polymorphisms should increase. (B) Genetic variation should increase. (C) Members of a breeding population should become more uniform in phenotype. (D) Neutral variation should decrease. (E) Genetic polymorphisms should increase.

73. Successfully breeding two individual organisms at a zoo and obtaining fertile offspring for several generations is no guarantee that the same could occur in nature (i.e., in the wild). Which species concept becomes difficult to confirm because of this fact? (A) biological (B) ecological (C) morphological (D) phylogenetic (E) paleontological

74. Which of the following is not considered an intrinsic isolating mechanism? (A) sterile offspring (B) ecological isolation (C) geographic isolation (D) gametic incompatibility (E) timing of courtship display

75. Some molecular data place the giant panda in the bear family (Ursidae) but place the lesser panda in the raccoon family (Procyonidae). The morphological similarities of these two species must therefore be due to (A) inheritance of acquired characteristics. (B) sexual selection. (C) inheritance of shared derived characters. (D) convergent evolution. (E) possession of shared primitive characters.

77. Which of the following has not yet been synthesized in laboratory experiments studying the origin of life? (A) liposomes (B) liposomes with selectively permeable membranes (C) oligopeptides and other oligomers (D) protobionts that use DNA to program protein synthesis (E) amino acids

78. What characteristic would all protobionts have had in common? (A) the ability to synthesize enzymes (B) a surrounding membrane or membrane-like structure (C) RNA genes (D) a nucleus (E) the ability to replicate RNA

79. Which of the following statements about bacterial cell walls is false? (A) Bacterial cell walls differ in molecular composition from plant cell walls. (B) Cell walls prevent cells from bursting in hypotonic environments. (C) Cell walls prevent cells from dying in hypertonic conditions. (D) Bacterial cell walls are similar in function to the cell walls of many protists, fungi, and plants. (E) Cell walls provide the cell with a degree of physical protection from the environment.

80. If penicillin is an antibiotic that inhibits enzymes from catalyzing the synthesis of peptidoglycan, then which prokaryotes should be most vulnerable to inhibition by penicillin? (A) mycoplasmas (B) gram-positive bacteria (C) archaea (D) gram-negative bacteria (E) spore-bearing bacteria

81. The strongest evidence for the endosymbiotic origin of eukaryotic organelles is the similarity between extant prokaryotes and which of the following? (A) nuclei and chloroplasts (B) mitochondria and chloroplasts (C) cilia and mitochondria (D) mitochondria and nuclei (E) mitochondria and cilia.

82. Which process allows nucleomorphs to be first reduced, and then lost altogether, without the loss of any genetic information from the host cell that ultimately surrounds the nucleomorph? (A) conjugation (B) horizontal gene transfer (C) binary fission (D) phagocytosis (E) meiosis