Question

why does density of dna decrease on heating

Answer 1

This tracks the unwinding and denaturation of DNA. The melting point (Tm) is the temperature at which half the DNA is unwound. DNA that consists entirely of AT base pairs melts at about 70° and DNA that has only G/C base pairs melts at over 100°.

Answer 2

Explanation:

With heating, the DNA does not decreased, but with the high temperature the hydrogen bond between the bases melts down, and the double helical structure of the double standard DNA breaks down into single standard DNA. In this stage, you can find the optical density in the single standard DNA and you can find some differences in the chromatin proteins level of different types of DNA due to increased temperature.