Scientists believe that the earth's early atmosphere lacked gas because photosynthetic organisms did not yet exist.
a) hydrogen
b) nitrogen
c) oxygen
d) sulfur

Students in biology are studying the macromolecules of life. they used a calorimeter to determine the calories in various types of food. once the lab was completed, the students ate the left over food samples. monica commented that in just 6 or 7 "chews" of the saltine, it was gone; nothing but a sticky paste in her mouth. elaborate on what happened chemically while chewing the saltine. include the macromolecules present.

What best describes emerging scientific ideas

Explain the causes and effect of damage to the genetic code.