In the United States, the parasite that causes malaria is not present, but African-Americans whose ancestors were from equatorial Africa are present
What should be happening to the sickle-cell allele in the United States, and what should be happening to it in equatorial Africa? A) stabilizing selection; disruptive selection
B) disruptive selection; stabilizing selection
C) directional selection; disruptive selection
D) directional selection; stabilizing selection
D
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Latex or resin canals evolved independently in more than 40 different lineages of plants
A. true B. false
The diffusion bioassay
A. determines the concentration of antimicrobial necessary to kill a bacteria. B. determines the concentration of antimicrobial necessary to inhibit growth of a bacteria. C. is similar in principle to the Kirby-Bauer test. D. determines the concentration of antimicrobial in a fluid. E. is similar in principle to the Kirby-Bauer AND determines the concentration of antimicrobial in a fluid.
The primary mycelium of basidiomycetes is dikaryotic
____________________ Indicate whether the statement is true or false.
Older roots can become extremely thick and woody as ________ accumulates during secondary growth.
A. Secondary phloem B. Sapwood C. Primary xylem D. Secondary xylem E. Primary phloem