When a Star Leaves the Main Sequence and Expands Toward

question 107

Multiple Choice

When a star leaves the main sequence and expands toward the red-giant region,what is happening inside the star?

• A) Hydrogen burning is taking place in a spherical shell just outside the core;the core itself is almost pure helium.
• B) Hydrogen burning is taking place in a spherical shell just outside the core;the core has not yet started thermonuclear reactions and is still mostly hydrogen.
• C) Helium burning is taking place in a spherical shell just outside the core;the core itself is almost pure carbon and oxygen.
• D) Helium is being converted into carbon and oxygen in the core.

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Definitions:

Jejunum

The mid-portion and the majority of the small intestine.

Small Intestine

A long, coiled tube where most of the digestion and absorption of nutrients from food takes place, extending from the stomach to the large intestine.

Protein

Essential nutrients required by the body for growth, repair, and maintenance of cells.

Trypsin

A pancreatic enzyme that digests proteins.