sodium-potassium pump. n. The enzyme-based mechanism that maintains correct cellular concentrations of sodium and potassium ions by removing excess ions from inside a cell and replacing them with ions from outside the cell.
Correct answer: A). Root
The part of the word that can not be broken down is called root word. In the word claustrophobic ''phob'' is the root word. It can not be suffix as a suffix are added after the root word. It cannot be prefixed as it is added before the root word. Here the prefix would be ''claustro'' and suffix would be ''ic''. It cannot be affixed as it contains both suffix and prefix.
Hence, the correct answer would be option A.
If by inadequate you mean not meeting the necessary levels (too low), then it is "hypo"
Answer:
In Branchiostoma, it is used mainly for feeding. The pharynx consists of numerous pharyngeal bars, with pharyngeal slits between them. The animal sucks in water through its mouth and forces it out through the pharyngeal slits, capturing small food particles from the water