MCQs on DNA Replication

What is the primary function of DNA helicase in replication?

• Synthesizes RNA primers

• Unwinds the DNA double helix

• Seals Okazaki fragments

• Relieves tension in DNA strands

Which enzyme synthesizes RNA primers during DNA replication?

• Primase

• DNA polymerase I

• Ligase

• Topoisomerase

What is the direction of new DNA strand synthesis?

• 3' to 5'

• 5' to 3'

• Bidirectional

• None of the above

Which strand is synthesized continuously during replication?

• Leading strand

• Lagging strand

• Both strands

• None of the above

What are the short fragments of DNA on the lagging strand called?

• Primers

• Nucleotides

• Okazaki fragments

• Polymerases

Which enzyme seals the gaps between Okazaki fragments?

• Helicase

• Ligase

• DNA polymerase III

• Topoisomerase

What is the role of single-strand binding proteins?

• Add nucleotides

• Relieve tension during unwinding

• Prevent reannealing of DNA strands

• Remove primers

Which enzyme removes RNA primers and replaces them with DNA?

• DNA polymerase I

• DNA polymerase III

• Ligase

• Primase

What structure forms at the site where DNA replication begins?

• Okazaki fragment

• Replication fork

• RNA primer

• Double helix

In prokaryotes, how many origins of replication are typically present?

• One

• Two

• Hundreds

• None