What type of bond holds bases together?

What type of bond holds bases together?

• A. Peptide bonds
• B. Covalent bonds
• C. Ionic bonds
• D. Hydrogen bonds

Answer: (D)

Bases in DNA are held together by hydrogen bonds. These are relatively weak, non-covalent attractions that form between complementary bases: adenine pairs with thymine via two hydrogen bonds, and guanine pairs with cytosine via three hydrogen bonds. This arrangement provides enough stability to keep the double helix intact, yet allows the strands to separate during replication and transcription. Peptide bonds connect amino acids in proteins, covalent bonds form the backbone within molecules, and ionic bonds involve full charges between ions—none of these are what couples the base pairs in DNA.

Bases in DNA are held together by hydrogen bonds. These are relatively weak, non-covalent attractions that form between complementary bases: adenine pairs with thymine via two hydrogen bonds, and guanine pairs with cytosine via three hydrogen bonds. This arrangement provides enough stability to keep the double helix intact, yet allows the strands to separate during replication and transcription. Peptide bonds connect amino acids in proteins, covalent bonds form the backbone within molecules, and ionic bonds involve full charges between ions—none of these are what couples the base pairs in DNA.