Fossils of the Earliest Life Are Very Difficult to Identify

question 53

Multiple Choice

Fossils of the earliest life are very difficult to identify in very old rocks because it

• A) was very simple and microscopic in size
• B) was not made of organic material that could be replaced by minerals
• C) was so different to life found on Earth today that we are not capable of identifying it
• D) did not leave behind any fossilized remains

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Definitions:

Bioaccumulation

The buildup of a persistent toxic substance, such as certain pesticides, in an organism’s body.

DDT

Dichloro-Diphenyl-Trichloroethane, a synthetic insecticide used historically for malaria and pest control, now banned in many countries due to environmental impact.

Nitrogen Cycle

A biogeochemical cycle that describes the transformations of nitrogen and nitrogen-containing compounds in nature.

Nitrogen Fixation

The process by which nitrogen gas from the atmosphere is converted into ammonia by certain bacteria, making nitrogen available to living organisms.