STRUCTURE OF MITOCHONDRION VERSUS CHLOROPLAST
Both the mitochondrion and the chloroplast:

• Are ovoid or elliptical in shape
• Are surrounded by an outer membrane and an inner membrane. In the mitochondrion, the term cristae is applied to the folds of the inner membrane.
• Have membranes surrounded by fluid. In the mitochondrion, the fluid matrix is inside the inner mitochondrial membrane, and fluid in the intermembrane space is between the inner and outer mitochondrial membranes. In the chloroplast, the stroma surrounding the grana is a fluid, and fluid also occupies the lumen of each thylakoid.