Q. If an isolated strain of DNA is kept at 80-90${^\circ}$C, then,
A) It changes into RNA
B) It breaks into two fragments
C) It breaks into many fragments
D) It uncoils and the two strands separate
Explanation
Heating of DNA strands at temperatures 80-90${^\circ}$C results to breakage of hydrogen bonds between nitrogen bases of two strands (denaturation). The strands show reunion on cooling (renaturation/annealing).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.