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

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.

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

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

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

83. A researcher wants to develop an assay (test) that will distinguish charophyceans and land plants from chlorophyte green algae. Which of the following chemicals would be the best subject for such an assay? (A) chlorophyll b-an accessory photosynthetic pigment (B) carotenoids-a class of accessory photosynthetic pigments (C) amylopectin-a starch-like food storage material (D) glycolate oxidase-an enzyme of peroxisomes that is associated with photorespiration (E) flavonoids-a class of phenolic compounds that is often associated with chemical signaling

84. Which of the following characteristics, if observed in an unidentified green organism, would make it unlikely to be a charophycean? (A) phragmoplast (B) peroxisome (C) apical meristem (D) chlorophylls a and b (E) rosette cellulose-synthesizing complex