Question

dna molecules are made up of two strands of nucleotides. strong covalent bonds form between the phosphate groups and the deoxyribose sugars in each strand to form the “backbones” of the dna molecule. weak attractive forces, called hydrogen bonds, form between the nitrogenous bases to hold the two strands together and form the rungs of the dna molecule’s ladder structure. unlike covalent bonds, weak hydrogen bonds can be easily broken. complete the paragraph. strong hydrogen weak hydrogen strong covalent weak covalent nitrogenous bases deoxyribose sugars the structure of a dna molecule resembles a twisted ladder. the sides of the ladder, or the backbones of the molecule, are formed by bonds between the phosphate groups and the. the rungs of the ladder are formed by bonds between the.

Explanation:

The backbone of DNA is formed by strong covalent bonds between phosphate groups and deoxyribose sugars. The rungs are formed by weak hydrogen bonds between nitrogenous bases.

Answer:

1. strong covalent
2. deoxyribose sugars
3. weak hydrogen
4. nitrogenous bases