Some questions must be answered with a cross in a box . If you change your mind about an
answer, put a line through the box and then mark your new answer with a cross .
Some scientists believe that mitochondria evolved from prokaryotic organisms.
They think that a prokaryotic organism entered a single-celled eukaryotic organism
and lived inside it. The two organisms evolved to become dependent on each other.
In the space below, draw and label a diagram to show the structure of a
mitochondrion.