Question

d. _________________ convert food into energy. they are found in plant and animal cells.

Explanation:

In cell biology (a subfield of Biology, which is part of Natural Science), the organelle that converts food into energy (through cellular respiration) and is present in both plant and animal cells is the mitochondrion (plural: mitochondria). Mitochondria are known as the "powerhouses" of the cell as they produce ATP (adenosine triphosphate), the energy currency of the cell.

Answer:

Mitochondria