For approximately how long was Earth populated exclusively by microscopic organisms?

a. 2 billion years
b. 500 million years
c. 750 million years
d. 3 billion years
e. 4 billion years


Answer: d. 3 billion years

Biology & Microbiology

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Modern cells are thought to have arisen from ____

a. protocells b. pre-cells c. gas and dust clouds d. prokaryotic cells that predated protocells e. prokaryotic cells that predated pre-cells

Biology & Microbiology

In prophase I of spermatogenesis, there are ____ chromatids

a. 23 b. 46 c. 69 d. 92 e. 115

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You are given an unknown organism to identify. It is unicellular and heterotrophic. It is motile, using many short extensions of the cytoplasm, each featuring the 9 + 2 filament pattern

It has well-developed organelles and two nuclei, one large and one small. This organism is most likely to be a _____. A) foraminiferan B) radiolarian C) ciliate D) kinetoplastid

Biology & Microbiology

You are playing a computer game for which you must create creatures to survive in particular environments. You species is sessile with a low chance of encountering a mate. The environment it lives in is unpredictable. The BEST mode of reproduction you could choose for your species would be:

What will be an ideal response?

Biology & Microbiology