What is the functional nature of the portal system and how does it differ from normal venous return flow?

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.

When the oxygen produced by photosynthetic plants in the water dissolves in the water, which of these is being formed?

What problem would a person most likely have if her kidney did not work correctly?