The Process of Accretion in Planetary Formation Is the

question 67

Multiple Choice

The process of accretion in planetary formation is the

• A) slow condensation by gravity of gas atoms into large, dense gas clouds that are the preplanetary masses.
• B) slow acquisition from deep space by the giant planets of their complement of moons by gravitational capture.
• C) slow accumulation of solid particles by gravity and collision into larger, solid objects.
• D) relatively rapid gravitational collapse (in less than 10⁶ years) of gas clouds to form planets.

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Definitions:

Cell Body

The part of the neuron that keeps it alive and determines whether or not it will fire.

Neurons

Cells within the nervous system that transmit information to other nerve cells, muscle, or gland cells.

Muscle Action

The contraction or relaxation of muscles which results in movement of body parts.

Acetylcholine

A neurotransmitter in the nervous system that plays a key role in muscle activation and also influences many functions in the brain.