Biologists Think That the First Photosynthetic Cells

question 14

Multiple Choice

Biologists think that the first photosynthetic cells

• A)used water as an electron donor.
• B)were the first living cells to develop.
• C)lived more than 2.8 billion years ago.
• D)released hydrogen into the atmosphere.
• E)required oxygen rather than carbon dioxide.

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Definitions:

Chemotherapy

A type of cancer treatment that uses drugs to kill or slow the growth of cancer cells.

Nausea

A sensation of unease and discomfort in the stomach with an urge to vomit.

Secondary Punisher

A stimulus that has acquired punishing properties through association with other punishers.

Criticism

The expression of disapproval of someone or something based on perceived faults or mistakes, or the analysis and judgment of the merits and faults of a literary or artistic work.