Even though nitrogen constitutes 78% of Earth's atmosphere, the amount available for living things nearly all comes from

A. a few groups of nitrogen-fixing bacteria.
B. the breakdown of minerals.
C. a few genera of detritivores.
D. nitrogen-containing fertilizers.
E. the breakdown of dead plants.


Answer: A

Biology & Microbiology

You might also like to view...

Why is it probably not a good idea to drink water directly from a mountain stream (i.e., untreated) even if it appears to

be unaffected by human activities?

What will be an ideal response?

Biology & Microbiology

Which stage in reproduction and development

occurs before the others? a. cleavage b. gamete formation c. gastrula formation d. zygote formation e. blastula formation

Biology & Microbiology

A phylogenetic tree grouping that consists of a common ancestor and all of its descendants is known as a ________ group

A) monophyletic B) paraphyletic C) polyphyletic D) polytomy

Biology & Microbiology

The symptoms of protozoan diseases are usually due to __________.

A) endotoxins B) capsules C) metabolic waste products D) exotoxins

Biology & Microbiology