Why Do Some Geologists Believe a Meteorite Impact Was Not

question 14

Multiple Choice

Why do some geologists believe a meteorite impact was not the sole cause of the extinction event at the end of the Mesozoic?

• A) Iridium is not always found at the boundary between Cretaceous and Paleogene rocks.
• B) Meteorite impacts cause local extinctions, not global extinctions.
• C) The meteorite hit at the end of the Jurassic, while extinctions occurred throughout the Cretaceous.
• D) The location of an impact crater has not been discovered, and likely never will be.
• E) Terrestrial and marine extinctions have not been shown to occur at the same time.

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Definitions:

Venous Valves

Structures within veins that prevent the backward flow of blood, crucial for blood returning to the heart.

Tunica Media

The middle layer of the wall of a blood vessel consisting mainly of smooth muscle cells and elastic fibers, responsible for regulating the diameter of the vessel.

Lumen

The inside space of a tubular structure, such as a blood vessel or intestine.

Carotid Sinus

A dilated area at the base of the internal carotid artery that contains receptors to help regulate blood pressure.