What unzip the dna ladder made of the doube helix?

In many humans, exposing the skin to sunlight over prolonged periods of time results in the production of more pigment by the skin cells (tanning). this change in skin color provides evidence that -

Dna, in the nucleus carries the genetic code for making proteins in ribosomes. in the diagram, b, represents the proteins produced. dna cannot leave the nucleus to carry the genetic information to the ribosome where proteins are produced. how does the genetic code get from the nucleus to the ribosome? what does a represent? now

Which of the following can be assumed about the layers in areas 2 and 4