Stars of Different Spectral Classes,O,B,A,F,G,K,M,show Differences in the Strengths of Absorption

question 2

Multiple Choice

Stars of different spectral classes,O,B,A,F,G,K,M,show differences in the strengths of absorption lines of various elements.These differences are due to differences in

• A)The chemical compositions of stars
• B)The surface temperatures of stars
• C)Stellar distances
• D)Stellar ages

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Definitions:

Enteric Nervous System

Known as the "second brain," this extensive mesh-like system of neurons controls the function of the gastrointestinal system.

Digestive Tract

The series of hollow organs joined in a long, twisting tube from the mouth to the anus, where digestion of food occurs.

Presynaptic Terminals

The ends of axons where neurotransmitters are stored before being released across the synaptic cleft to transmit nerve impulses.

Axons

Long, threadlike extensions of a nerve cell that transmit electrical impulses away from the neuron's cell body.