Which of the following features do all gas exchange systems have in common Group of answer choices they are found only in animals they are exposed to air they are maintained at a constant temperature they are enclosed within ribs the exchange systems are moist

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.