Question

why are mitochondria sometimes called the powerhouse of cells? they are the site of photosynthesis. mitochondria are not called the powerhouse of cells. they are the site of cellular respiration.

Explanation:

Mitochondria are organelles in cells. Cellular respiration is a process that generates energy (ATP). Mitochondria carry out cellular respiration. So they are called the powerhouse of cells. Photosynthesis occurs in chloroplasts (in plant cells). And mitochondria are indeed called the powerhouse of cells.

Answer:

They are the site of cellular respiration.