Guard Cells

question 17

Multiple Choice

Guard cells

• A) surround the stoma.
• B) control the opening to the interior of the leaf.
• C) become swollen when it becomes light, if environmental conditions are not too hot or dry.
• D) absorb water from surrounding epidermal cells.
• E) do all of these.

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Definitions:

Electron Donors

Atoms, molecules, or ions that provide electrons to other atoms, molecules, or ions during chemical reactions, often resulting in the reduction of the latter.

Alkylamine

A compound resulting from the replacement of one or more hydrogen atoms of ammonia (NH3) with alkyl groups.

α-Carbon

The first carbon atom attached directly to a functional group in an organic molecule.

Chemical Shift

A term used in nuclear magnetic resonance (NMR) spectroscopy to describe the change in the resonance frequency of a nucleus due to its chemical environment.