AP BIOLOGY

Detailed explanation-1: -Hydrogen bonds occur between the two strands and involve a base from one strand with a base from the second in complementary pairing. These hydrogen bonds are individually weak but collectively quite strong. a template during DNA replication.

Detailed explanation-2: -Hydrogen bonds do not involve the exchange or sharing of electrons like covalent and ionic bonds. The weak attraction is like that between the opposite poles of a magnet. Hydrogen bonds occur over short distances and can be easily formed and broken.

Detailed explanation-3: -The nitrogen bases form the double-strand of DNA through weak hydrogen bonds. The nitrogen bases, however, have specific shapes and hydrogen bond properties so that guanine and cytosine only bond with each other, while adenine and thymine also bond exclusively.

Detailed explanation-4: -Each DNA molecule consists of two nucleotide chains wrapped around each other in a double helix and held together by hydrogen bonds. This hydrogen bonding involves only the nitrogenous bases.

Detailed explanation-5: -Answer and Explanation: Weak hydrogen bonds hold together the two strands of DNA to form a double helix. These hydrogen bonds are formed between the nitrogenous bases. Two hydrogen bonds can form between thymine and adenine while three hydrogen bonds can form between guanine and cytosine.