Life probably would never have emerged on Earth if the ancient atmosphere had been the same as the present one in
regard to the content of ____.
a. carbon dioxide
b. hydrogen
c. oxygen
d. nitrogen
e. carbon monoxide
ANSWER: c
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Which region(s) of a gene are not found within the mRNA transcript?
A) promoter region B) termination region C) stop codon D) promoter and stop codon E) promoter and termination region
Ovules develop within the ovary, which is located in the swollen lower portion of which floral organ?
A. stamen B. stigma C. anther D. filament E. pistil
Because it is possible for a female to mate with multiple males, any of whom could be the father, male mammals and birds always:
a. invest more in the care of the offspring. b. be the choosier sex in mating. c. have some degree of paternity uncertainty. d. invest less in the care of the offspring. e. mate with kin that they can trust.
A biologist is studying how pollution affects algal growth and snail populations in a portion of Lake Erie. What level of organization is she studying?
a. population b. community c. ecosystem d. cells