18. which process does the plant need energy to perform? a. absorbing water into the root hairs ob. release of oxygen into the atmosphere c. transpiration of water od. pulling nutrients into the root hairs

OD. Pulling nutrients into the root hairs

Explanation:

Uptake of minerals, ions into root hairs from the soil is done on the expense of energy. This type of absorption is called active transport because minerals are in higher concentration in the root hairs as compared to the soil. Plants need more nutrients such as amino acids on the expense of energy actively.  

the answer is b.) hydrogen bonds between bases.

answer: substrate concentration. enzymes work best when there is a high enough substrate concentration for the reaction they catalyse.