All 4 of the macromolecules that make up living things are all based molecules, making them organic molecules.
a. oxygen
b. carbon
c. hydrogen
d. nitrogen

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.