Nitrogen makes up about _________% of the Earth’s

atmosphere.
a. 20
b. 40
c. 60
d. 80
e. 90


Answer: d

Biology & Microbiology

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One application of the knowledge of sugar flow in xylem allows for the collecting of sap from maple trees in the:

A. summer B. winter C. fall D. early spring E. None of these is correct

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In flowering plants how many egg cells are typically produced from each megaspore mother cell?

a. 1 b. 2 c. 3 d. 4 e. 8

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How do viruses gain entry into cells?

What will be an ideal response?

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Choose the letter of the best match from the following:A. Third trimester of pregnancyB. Second month of pregnancyC. First month of pregnancyD. Second trimester of pregnancyE. Third month of pregnancyNeurulation occurs.

What will be an ideal response?

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