Nucleotides in a DNA strand are linked together by which type of bonds?

Nucleotides in a DNA strand are linked together by which type of bonds?

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

Answer: (B)

Nucleotides in a DNA strand are joined by covalent phosphodiester bonds to form the sugar-phosphate backbone. Each bond links the phosphate of one nucleotide to the 3' carbon of the adjacent sugar, creating a repeating chain that runs from 5' to 3'. This strong covalent linkage provides stability and directionality to the strand. The hydrogen bonds between complementary bases hold the two strands together in the double helix, but they are not the bonds that connect nucleotides along a single strand. Peptide bonds connect amino acids in proteins, and ionic interactions are not responsible for linking nucleotides in DNA.

Nucleotides in a DNA strand are joined by covalent phosphodiester bonds to form the sugar-phosphate backbone. Each bond links the phosphate of one nucleotide to the 3' carbon of the adjacent sugar, creating a repeating chain that runs from 5' to 3'. This strong covalent linkage provides stability and directionality to the strand. The hydrogen bonds between complementary bases hold the two strands together in the double helix, but they are not the bonds that connect nucleotides along a single strand. Peptide bonds connect amino acids in proteins, and ionic interactions are not responsible for linking nucleotides in DNA.