How Do Nitrogen-Fixing Microbes First Become Associated with Their Symbiotic

question 154

Multiple Choice

How do nitrogen-fixing microbes first become associated with their symbiotic plants?

• A) They are carried in the seed.
• B) They move into the vascular system and multiply.
• C) They move in via openings in the plant cell walls.
• D) They enter via modified root hairs.
• E) They enter root nodules once they are produced by the plant.

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Definitions:

Cardiac Output

The volume of blood the heart pumps through the circulatory system in one minute, an important measure of cardiovascular health.

End-Diastolic Volume

The volume of blood in the ventricle at the end of the filling phase, or diastole, of the heart's cycle.

Venous Return

The flow of blood back to the heart through the veins, critical for maintaining cardiovascular function.

Cardiac Cycle

The cardiac cycle is the sequence of events that occurs during one heartbeat, involving the contraction (systole) and relaxation (diastole) of the atria and ventricles to pump blood throughout the body.