because fish, penguins, and dolphins are aquatic animals. It can't be A. because if it were vestigial it would be useless. It can't be B even though it does seem like the right answer because the are all aquatic. It can't be C. because it would been that the same species would have the same niche which is not possible. It can't be D. because every organism is evolved from a common ancestor.
The animal cells get the organic compounds by eating plants. The only form of energy a cell can use is a molecule called adenosine triphosphate (ATP). Chemical energy is stored in the bonds that hold the molecule together.
