Q. When DNA replication starts
A) The leading strand produces Okazaki fragments
B) The hydrogen bonds between the nucleotides of two strands break
C) The phosphodiester bonds between the adjacent nucleotides break
D) The bonds between the nitrogen base and deoxyribose sugar break
Explanation
On starting of DNA replication, the two strands of DNA double helix unwind with the help of DNA unwinding protein (also called helicase). The unwinding occurs as this protein begins its binding with DNA strands, thus, breaking the hydrogen bonds between complementary nitrogenous bases.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.