Watson and crick built models that demonstrated that: a. dna and rna have the same structure b. dna is made of two strands that twist into a double helix c. guanine forms hydrogen bonds with adenine d. thymine forms hydrogen bonds with cytosine

Why do leaves change color in the fall? green pigments break down and no longer mask the color of chlorophyll. chlorophyll breaks down and no longer masks the colors of other pigments. red- and yellow-colored pigments grow and mask green-colored chlorophyll. green-colored chlorophyll breaks down and turns red and yellow.

What percentage of light hits earth's surface directly?

Nh3 +02-no + h20 is unbalanced what is the balanced equation