Question

DNA is made of two chains of nucleotides. Which type of bonds hold the chains together?

hydrogen bonds
covalent bonds
ionic bonds
polar covalent bonds

Answer 1

Hydrogen bonds

Step-by-step explanation:

DNA is a double helical structure that means two nucleotide chains are bonded together. The bonds through which two nucleotide chains are held together are known as hydrogen bonds. DNA is made up of four types of nucleotides named as adenine (A), thiamine (T), cytosine (C) and guanine (G). Out of these four, adenine is complimentary to thiamine and if adenine is present in one nucleotide chain then it bonds with thiamine of other nucleotide chain with the help of two hydrogen bonds while cytosine is complimentary to guanine and bonds with guanine of other nucleotide chain with the help of three hydrogen bonds.

Answer 2

hydrogen bonds

Step-by-step explanation:

The two strands of DNA nucleotides are joined together by bonds called hydrogen bonds, which form between the nitrogenous bases of each strand. Base pairing occurs precisely: a purine base binds to a pyrimidine - adenine (A) in one chain paired with thymine (T) in the other and guanine (G) paired with cytosine (C).