Fossils of the Earliest Known True Hominids Are Approximately How

question 68

Multiple Choice

Fossils of the earliest known true hominids are approximately how many millions of years old?

• A)more than 20
• B)about 10
• C)between 5 and 2
• D)less than 0.5
• E)none of these

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Definitions:

Protein

Large, complex molecules made up of amino acids that play many critical roles in the body, including providing structure to cells and facilitating biological reactions.

Irreversible Change

A permanent alteration of a substance or system from which recovery or return to the original condition is impossible under normal conditions.

Enzymes

Biological molecules that significantly speed up the rate of virtually all of the chemical reactions that take place within cells.

Organic Compounds

Chemical compounds that contain carbon-hydrogen bonds, including a wide range of substances such as fuels, plastics, food additives, and drugs.