They are organisms (individual organisms called "plankters") that live in large bodies of water.
Explanation:
They reside in large bodies of water (oceans, lakes, etc). They are usually abundant in surface waters because all ecosystems of plankton live off input of solar energy.
Answer: The right side of the brain controls the left side of the body and vice versa So if damage occurs on the right side of the brain that controls the movement of the arm, the left arm may be weak or paralyzed.