Answer:
mitochondria contain membrane folds called cristae, whereas chloroplasts contain vesicles in stacks called grana
Explanation:
Mitochondria are composed of two membranes (i.e., the inner and outer membranes), which are separated by the intermembrane space. The inner mitochondrial membrane is composed of several folds that form the cristae, which extend into the mitochondrial matrix. On the other hand, in chloroplasts, the inner membrane consists of interconnected stacks of sacs named thylakoids, whose arrangement is known as grana.