Biostratigraphic Dating Relies on

question 48

Multiple Choice

Biostratigraphic dating relies on

• A)the first and last appearances of species in the fossil record.
• B)magnetic shifts in the earth's interior.
• C)radioactive decay of carbon to nitrogen.
• D)the concentration of fluorine in the soil and in groundwater.

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Definitions:

Macrophages

A type of phagocytic cell found in the liver, spleen, lungs, bone marrow, and connective tissue. Macrophages play several roles in humoral and cell-mediated immunity, including presenting the antigens to the lymphocytes involved in these defenses; also known as monocytes while in the bloodstream.

Hepatocytes

The cells within the lobules of the liver. Hepatocytes process nutrients in the blood and make bile.

Pepsinogen

An inactive precursor of pepsin, an enzyme produced in the stomach that plays a crucial role in the digestive process by breaking down proteins.

Pepsin

An enzyme that allows the body to digest proteins.