How many mass extinctions have occurred over all of geologic history?

a. one
b. two
c. three
d. four
e. five


ANSWER: e

Biology & Microbiology

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An activator is to an enhancer as a(n) _____ is to a silencer.

A. transcription factor B. inducer C. repressor D. mediator E. RNA polymerase II

Biology & Microbiology

Sympatric species are

A. more likely than allopatric species to display character displacement. B. always show character displacement. C. less likely than allopatric species to display character displacement. D. unlikely to be competing. E. more likely than allopatric species to display character displacement, less likely than allopatric species to display character displacement, and unlikely to be competing.

Biology & Microbiology

In which stage do chromosomes start acting independently/ no homologous pairs

What will be an ideal response?

Biology & Microbiology

What newly identified organism has been discovered to live on our skin

a. Methanobacterium b. Staphylococcus c. Nanoarchaeum d. Thaumarchaeota e. Ignicoccus

Biology & Microbiology