When did HIV-1 makes its 1st appearance in the United States?
a. 1966
b. 1999
c. 1981
d. 1992
e. 1969
e
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You transform bacteria with a plasmid carrying the ampicillin-resistance gene ampR. How would you determine which bacteria took up the plasmid?
A. Bacteria containing the plasmid would be able to grow in the absence of ampicillin. B. Bacteria containing the plasmid would be able to produce ampicillin. C. Bacteria containing the plasmid would turn blue. D. Bacteria containing the plasmid would be able to grow in the presence of ampicillin. E. Ampicillin-resistance is necessary for the plasmid DNA to get into the bacteria.
Strenuous exercise lowers the blood pH, causing the curves for both hemoglobin and myoglobin to shift to the right. This shift results in
(A) an unloading of O2 at higher partial pressures (B) an increase in the number of O2-binding sites (C) the capture of more O2 by hemoglobin (D) the capture of more O2 by myoglobin
The movement of chemicals through ecosystems is known as
A. gross primary production. B. biogeochemical cycling. C. community ecology. D. net primary production. E. biomagnification.
Protein filaments that function in muscular contraction are
A. keratin and actin. B. myosin and collagen. C. elastin and collagen. D. actin and myosin. E. elastin and keratin.