Which structures are most similar in birds and mammals based on their functions? air sacs in birds and rib cages in mammals
air sacs in birds and mammary glands in mammals
gizzards in birds and teeth
crops in birds and teeth in mammals
mammals

Explain why in any given geographical region, women tend to have lighter skins( by 3-4% on average) than men?

Pepsin is an enzyme in the stomach that breaks polypeptides into amino acids. pepsin functions best at a ph of around 1.5. what would be the most likely result if the ph of the stomach were increased to 5

Indicate whether the following statements about the biases in the fossil record are true or false. a) inland species are more likely to be preserved than marine species b) organisms with hard body parts are more likely to be preserved than are those composed soft tissues. c) species that existed over a larger area are more likely to be preserved than species existing over a smaller area. d) organisms that lived very long ago are more likely to be found as fossils than organisms that lived relatively recently e) the fossils of larger organisms are more likely to be found than the fossils of smaller organisms