Which of the Following Statements Accurately Describes the Effect of the Permian

question 12

Multiple Choice

Which of the following statements accurately describes the effect of the Permian and Cretaceous extinctions on the percentage of prey organisms in marine environments?

• A) After the Permian and Cretaceous extinctions, the percentages of prey organisms increased.
• B) After both the Permian and Cretaceous extinctions, the percentages of prey organisms decreased.
• C) After the Permian extinction the percentage of prey organisms decreased, but after the Cretaceous extinction the percentage of prey organisms continuously increased.
• D) After the Permian extinction the percentage of prey organisms remained stable, but after the Cretaceous extinction the percentage of prey organisms increased.

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Definitions:

Postsynaptic Membrane

The part of the nerve cell membrane that is on the receiving end of a synapse, responding to neurotransmitters released by the presynaptic neuron.

Synaptic Cleft

The narrow gap between the terminal end of a neuron and the neighboring neuron or muscle cell, across which neurotransmitters are released to transmit signals.

Schwann Cell

A type of glial cell that forms the myelin sheath around nerve fibers in the peripheral nervous system.

Neuron Cell Body

Enlarged portion of the neuron containing the nucleus and other organelles; also called nerve cell body.