The first vertebrates appear in the fossil record during the

A. Cambrian Period.
B. Proterozoic Era.
C. Carboniferous Period.
D. Triassic Period.
E. Devonian Period


A. Cambrian Period.

Biology & Microbiology

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Which of the following is not a vector?

A. Fomite B. Human C. Fly D. Flea E. Fomite AND human

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Male zebra finches behave differently toward familiar neighbors, whom they largely ignore, and unfamiliar singers,

whom they attack and drive away. This behavior is a result of ____.

a. operant conditioning b. classical conditioning c. cognition d. imprinting e. habituation

Biology & Microbiology

The modern evolutionary synthesis of the 1930s and 1940s melded together Darwin's findings with ________

A) genetics B) sociology C) psychology D) chemistry

Biology & Microbiology

Polar microtubules

a. overlap in the center of the spindle. b. are attached to the contractile ring. c. are attached to kinetochores. d. pull kinetochores poleward.

Biology & Microbiology