How can animals have difficulty getting energy

Cells are adapted to preform specific functions. which of the following terms refers to this capability?

9. the history of life on earth is recorded in

The embryos of a bird, a reptile, and a mammal are similar in appearance. how does comparing the physical appearance of embryos of different species support the theory of evolution? a. it shows that these organisms share a common ancestor. b. it provides evidence that these organisms eat the same foods.c. it shows that these organisms share the same habitat.d. it provides evidence that these organisms suffered a genetic mutation.