Final answer:
Plants require mitochondria primarily to produce ATP, which is the main source of energy for the cell, through the process of cellular respiration.
Step-by-step explanation:
Plants need mitochondria to produce ATP. Scientists often refer to mitochondria as the "powerhouses" or "energy factories" of both plant and animal cells because they are responsible for making adenosine triphosphate (ATP), the primary energy-carrying molecule for the cell. This process is known as cellular respiration, which uses the chemical energy in glucose and other nutrients, and in the presence of oxygen, produces carbon dioxide as a waste product. While mitochondria do play a role in the metabolism of lipids, their primary function is to provide energy for the cell through the generation of ATP.