The Distance to the Nearest,large,spiral Galaxy,Andromeda,is 2

question 38

Multiple Choice

The distance to the nearest,large,spiral galaxy,Andromeda,is 2.5 million light-years.How long does it take light to travel from us to Andromeda?

• A) 360 years
• B) 1.2 thousand years
• C) 4.5 billion years
• D) 2.5 million years

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Definitions:

Reticular Formation

A network of neurons located in the brainstem that plays a key role in controlling arousal, wakefulness, and focusing attention.

Sleep

A state of rest characterized by altered consciousness, reduced activity, and a decreased response to external stimuli.

Arousal

A physiological and psychological state of being awake or reactive to stimuli, often associated with increased heart rate, alertness, and energy.

Medulla

A portion of the brainstem involved in autonomic functions such as breathing, heart rate, and blood pressure.