When Did the Most Severe Mass Extinction on Earth Occur

question 19

Multiple Choice

When did the most severe mass extinction on Earth occur?

• A)at the end of the Cambrian
• B)at the end of the Devonian
• C)at the end of the Jurassic
• D)at the end of the Permian

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Definitions:

Recurrent Heart Attacks

Experiencing multiple episodes of myocardial infarction, which is the interruption of blood supply to a part of the heart, causing heart cells to die.

Mortality

The state of being subject to death; often used in statistics to refer to the rate of death in a population.

Catecholamines

A class of neurotransmitters that includes dopamine, norepinephrine, and epinephrine, playing important roles in the body's stress response and emotional arousal.

Cytokines

Small proteins that are important in cell signaling. They are released by cells and affect the behavior of other cells, and sometimes the releasing cell itself.