The Organisms That Produced the Oxygen Gas in Earth's Early

question 122

Multiple Choice

The organisms that produced the oxygen gas in Earth's early atmosphere were

• A) anaerobic eukaryotes.
• B) aerobic eukaryotes.
• C) photosynthetic prokaryotes.
• D) aerobic prokaryotes.
• E) completely unlike modern organisms.

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Definitions:

Method of Concomitant Variations

A research method where one observes the effects of the deliberate variation of one factor on a phenomenon to identify causation.

Necessary Condition

A necessary condition is a condition that must be present for an event or state of affairs to occur; without it, the event or state cannot exist.

Sufficient Condition

A condition or set of conditions that, if satisfied, ensures that a certain statement or outcome must be true.

Method of Concomitant Variations

A scientific principle stating that if two variables vary together in a consistent manner, then one may be a cause of the other.