The Binding of the Neurotransmitter Acetylcholine to the Nicotinic-Muscle Receptors

question 34

Multiple Choice

The binding of the neurotransmitter acetylcholine to the nicotinic-muscle receptors at the neuromuscular junction enables:

• A) potassium ions to move into the cells.
• B) sodium ions to move out of the cells.
• C) sodium ions to move into the cells.
• D) magnesium ions to enter the cells.

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Definitions:

Chordates

A large phylum of animals that includes all vertebrates as well as two groups of invertebrates, characterized by having a notochord at some stage of their development.

Ediacaran Fauna

Ediacaran fauna is a group of animal species that existed during the Ediacaran period, just before the Cambrian. The oldest Ediacaran fossils are about 570 million years old. Ediacarans included diverse species that looked like fronds, geometrical disks, and blobs covered with tire tracks. They appear to have become extinct 540 million years ago, although some researchers argue that certain Ediacaran taxa belong to extant animal clades.

Extinction

Refers to the permanent loss of a species. It is marked by the death or failure to breed of the last individual.

Stromatolites

Layered structures formed by the mineralization of bacteria.