The Colonization of Land by Plants Appears to Have Begun

question 14

Multiple Choice

The colonization of land by plants appears to have begun about

• A) 545 million years ago
• B) 360 million years ago
• C) 65 million years ago
• D) 475 million years ago

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Definitions:

Collagen and Elastin Fibers

Proteins present in connective tissues, where collagen provides strength and elastin allows for elasticity.

Macrophages

A variant of white blood cell that is specialized in ingesting and decomposing cellular remnants, alien substances, pathogens, and cancerous cells by means of a procedure referred to as phagocytosis.

Arrector Pili

Small muscles attached to hair follicles that, when contracted, cause hair to stand on end - a phenomenon often associated with cold or fright, known as "goosebumps."

Dermal Root Sheath

The part of the hair follicle that provides a protective layer and is involved in hair growth, derived from the dermis.