Say you were traveling up a mountain, where would you have the most trouble breathing? At the bottom of the mountain or at the top of the mountain? Describe why.

Explain how sequences of amino acids in proteins can be used to reveal relationships among organisms.

12) several teeth were found in an area of flat land covered with trees and plants. the teeth were examined by a paleontologist, and it was determined that the teeth came from a shark. they found many other shark teeth in this area. however, the people who discovered the teeth were puzzled, because there was no source of water near where the fossils were found. what is the paleontologist's best explanation for why the teeth were found in this area? a) sharks used to live on flat land. b) this area was once covered with salt water. c) this area was once covered with freshwater. d) someone buried the shark teeth deep in the ground.

¿cómo demostraron los experimentos de griffith que un factor hereditario estaba involucrado en la transformación bacteriana?