LIFE SCIENCE

Detailed explanation-1: -Each molecule of DNA is a double helix formed from two complementary strands of nucleotides held together by hydrogen bonds between G-C and A-T base pairs. Duplication of the genetic information occurs by the use of one DNA strand as a template for formation of a complementary strand.

Detailed explanation-2: -DNA base pair. Under normal circumstances, the nitrogen-containing bases adenine (A) and thymine (T) pair together, and cytosine (C) and guanine (G) pair together. The binding of these base pairs forms the structure of DNA .

Detailed explanation-3: -The human genome is thus said to contain 3 billion nucleotide pairs, even though most human cells contain 6 billion nucleotide pairs. DNA is a double helix: Each nucleotide on a strand of DNA has a complementary nucleotide on the other strand.

Detailed explanation-4: -A DNA molecule is made up of two linked strands that wind around each other to resemble a twisted ladder in a helix-like shape. Each strand has a backbone made of alternating sugar (deoxyribose) and phosphate groups. Attached to each sugar is one of four bases: adenine (A), cytosine (C), guanine (G) or thymine (T).