The oldest fossils of eukaryotic cells are about ________ years old. 

A. 1.8 billion
B. 3.5 billion
C. 500 million
D. 100 million


A. 1.8 billion

Biology & Microbiology

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Oak trees and many other plant species have years in which they have synchronous production of many progeny by all individuals in a population. This is known as

A. sympatry. B. crypsis. C. armorment. D. masting. E. None of the choices are correct.

Biology & Microbiology

A molecule of water in the middle of a chunk of ice will usually have ____ hydrogen bonds with other water

molecules.

a. 2 b. 3 c. 3.4 d. 4 e. 6

Biology & Microbiology

The maximum volume of air that can be expired following a resting expiration is called

A) tidal volume. B) vital capacity. C) expiratory reserve volume. D) inspiratory reserve volume. E) inspiratory capacity.

Biology & Microbiology

The causative agents of bubonic plague, which killed 100 million people during the 14th century, were

A) viruses. B) fish. C) fleas. D) rats. E) bacteria.

Biology & Microbiology