Channel Proteins Allow Ions That Would Not Normally Pass Through

question 28

Multiple Choice

Channel proteins allow ions that would not normally pass through the cell membrane to pass through via the channel.The property of the channel protein that makes this possible is its pore, which is composed of

• A) polar amino acid groups.
• B) hydrophobic amino acid groups.
• C) Ca²⁺.
• D) carbohydrates.
• E) nonpolar R groups.

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Definitions:

Endodermal Cell

An endodermal cell is a type of cell originating from the innermost layer of the early embryo, contributing to the formation of the lining of the digestive and respiratory systems.

Stele

The cylinder in the center of roots and stems that contains the vascular tissue; also called vascular cylinder.

Pericycle

A layer of cells found just inside the endodermis in plant roots, involved in the formation of lateral roots and secondary growth.

Endodermis

The innermost layer of cells in the root cortex, serving as a selective barrier that regulates the passage of substances from the soil into the vascular cylinder.