Final answer:
The joining of sticky ends involves the formation of phosphodiester bonds between nucleotide bases, contributing to the polymerization of nucleotides into nucleic acid strands.
Step-by-step explanation:
In a nucleic acid strand, the joining of sticky ends involves the formation of phosphodiester bonds between the nucleotide bases. These bonds are covalent bonds formed between the 5' phosphate group of one nucleotide and the 3' hydroxyl group of another nucleotide. They contribute to the polymerization of nucleotides into nucleic acid strands.
For example, when two single-stranded DNA molecules with complementary sticky ends come together, the sticky ends anneal through hydrogen bonding between their complementary bases. DNA ligase can then join the two sugar-phosphate backbones of the DNA through the formation of phosphodiester bonds, creating a continuous double-stranded DNA molecule.