Which enzyme reads the parent DNA strand and creates a complementary, antiparallel daughter strand?

Which enzyme reads the parent DNA strand and creates a complementary, antiparallel daughter strand?

• A. DNA helicase
• B. DNA polymerase
• C. DNA ligase
• D. Primase

Answer: (B)

DNA polymerase copies the template by reading the parent strand and inserting nucleotides that pair with it, producing a complementary daughter strand. It reads the template in the 3' to 5' direction and synthesizes the new strand 5' to 3', so the newly built strand runs antiparallel to the template. This combination of reading direction and 5' to 3' synthesis ensures the copy is both complementary and antiparallel. Other enzymes have different roles: helicase unwinds the DNA, primase provides the RNA primer to start synthesis, and ligase seals the backbone after fragments on the lagging strand.

DNA polymerase copies the template by reading the parent strand and inserting nucleotides that pair with it, producing a complementary daughter strand. It reads the template in the 3' to 5' direction and synthesizes the new strand 5' to 3', so the newly built strand runs antiparallel to the template. This combination of reading direction and 5' to 3' synthesis ensures the copy is both complementary and antiparallel. Other enzymes have different roles: helicase unwinds the DNA, primase provides the RNA primer to start synthesis, and ligase seals the backbone after fragments on the lagging strand.