Hypothesis I: A flavin pigment absorbs blue light; this pigment then activates the proton pump.Hypothesis II: When CO2 concentration rises, a membrane receptor inactivates the proton pump.Which hypothesis is supported by the fact that cells of wilting leaves produce abscisic acid, which causes guard cells to close?
A. Supports both hypothesis I and II.
B. Supports only hypothesis I.
C. Supports only hypothesis II.
D. Supports neither hypothesis.
Answer: D
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You are walking along the beach and see the remains of an unknown animal washed up on shore. You examine its characteristics and see that it is gelatinous, transparent, bilaterally symmetric, and lacks tentacles. You provisionally identify its phylum according to which choice?
a. Gelatinous body rules out Cnidaria. b. Lack of tentacles rules out Cnidaria. c. Bilateral symmetry rules out Platyhelminthes. d. Transparent body rules out Ctenophora.
The common human parasite Giardia lamblia
a. can cause diarrhea. b. is a bacterium. c. multiplies very slowly. d. uses pseudopodia for locomotion. e. is involved in many heart attacks.
Transgenic animals
A. are often obtained from germline engineering. B. will pass the genes on to their offspring. C. can be engineered to become factories for manufacturing proteins. D. commonly include mice. E. All of the choices are correct.
Island arcs are associated with:
a. midocean ridges. b. continental shelves. c. continental slopes. d. deep sea trenches.