DNA Replication Processes and Enzymes

DNA replication is the process of duplicating a DNA molecule to ensure genetic information is passed to the next generation of cells. The process involves two strands: the leading strand, which is replicated continuously, and the lagging strand, which is replicated in fragments called Okazaki fragments. Enzymes like DNA helicase and DNA polymerase play crucial roles in unwinding the DNA and adding nucleotides. The leading strand is synthesized in the same direction as the replication fork, while the lagging strand is synthesized in the opposite direction, requiring DNA ligase to join the fragments. The result is two identical DNA molecules that form a double helix.

What is the primary purpose of DNA replication?

• To create proteins

• To produce RNA

• To duplicate genetic information for new cells

• To repair damaged DNA

Which enzyme is responsible for unwinding the DNA strands during replication?

• RNA polymerase

• DNA polymerase

• DNA ligase

• DNA helicase

In which direction does DNA polymerase add nucleotides on the leading strand?

• 5' to 3'

• 3' to 5'

• Both directions

• Randomly

What is the role of DNA polymerase in DNA replication?

• To synthesize RNA

• To join Okazaki fragments

• To add complementary nucleotides

• To unwind the DNA strands

What is the main difference in the replication process between the leading and lagging strands?

• The leading strand is synthesized continuously, while the lagging strand is synthesized in fragments.

• The leading strand requires more enzymes than the lagging strand.

• The leading strand is synthesized in the nucleus, while the lagging strand is synthesized in the cytoplasm.

• The leading strand uses different nucleotides than the lagging strand.

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

• Okazaki fragments

• Polymerase fragments

• Helicase fragments

• Ligase fragments

Which enzyme is responsible for joining Okazaki fragments on the lagging strand?

• DNA polymerase

• DNA helicase

• RNA primase

• DNA ligase

How do DNA polymerase and helicase work on the lagging strand compared to the leading strand?

• They work faster on the lagging strand.

• They do not work on the lagging strand.

• They work in opposite directions on the lagging strand.

• They work in the same direction on both strands.

What is the final result of DNA replication?

• Two identical RNA molecules

• Two identical DNA molecules

• One new DNA and one new RNA molecule

• Two different DNA molecules

Why is the DNA replication process considered semi-conservative?

• Each new DNA molecule contains one old and one new strand.

• Both new DNA molecules are completely new.

• Each new DNA molecule contains two old strands.

• Both new DNA molecules are identical to each other but not to the original.