The Following Questions Refer to the Sketch Below of an H-R

question 43

Multiple Choice

The following questions refer to the sketch below of an H-R diagram for a star cluster.

-Based on its main-sequence turnoff point,the age of this cluster is

• A)less than 1 billion years.
• B)about 1 billion years.
• C)about 2 billion years.
• D)about 10 billion years.
• E)more than 15 billion years.

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Definitions:

Agonists

Drugs that enhance a neurotransmitter’s activity.

Antidepressants

Medications designed to improve symptoms of depression by altering chemical balances in the brain.

Synaptic Reuptake

The presynaptic neuron’s process of reabsorbing its own neurotransmitters after signaling so that they can be released again the next time the neuron fires.

Neurotransmitters

Chemical substances that transmit signals across a synapse from one neuron to another in the brain, influencing various bodily functions and behaviors.