Which term describes the process of pairing complementary strands to form a double-stranded DNA molecule, often during primer annealing?

• A. Ligate
• B. Anneal
• C. Hybridize
• D. Transform

Answer: (B)

Base pairing between complementary bases forms a double-stranded DNA molecule. After the strands are separated by heat, the reaction cools so primers can bind to their matching sequences on the template. This specific binding step is called annealing, and it depends on the right temperature to promote correct hydrogen bonding between primer and target without encouraging nonspecific interactions. Ligating means joining DNA ends with a ligase, which is a different process. Transform refers to introducing DNA into cells. Hybridize is a broader term for base pairing in various contexts, but in this situation the precise term for primer binding is annealing.