Question

1. what type of bond holds base pairs together? a covalent b hydrogen c ionic d peptide

Explanation:

In DNA, base pairs (such as adenine - thymine and guanine - cytosine) are held together by hydrogen bonds. Covalent bonds are involved in the sugar - phosphate backbone of DNA. Ionic bonds are formed by the transfer of electrons between atoms (not relevant here). Peptide bonds are found in proteins (between amino acids), not in DNA base - pairing.

Answer:

B. Hydrogen