Question

folds on the inner membrane of a mitochondrion are called the _______
o microtubules
o thylakoids
o cristae
o matrix

Explanation:

Mitochondria have inner - membrane folds. Microtubules are part of the cytoskeleton. Thylakoids are in chloroplasts. The matrix is the space inside the inner membrane, not the folds. Cristae are the folds on the inner membrane of a mitochondrion, which increase the surface area for ATP - generating reactions.

Answer:

C. cristae