DNA Replication Concepts and Mechanisms

The video tutorial explains the identification of leading and lagging strands in DNA replication. It covers the role of DNA helicase in unzipping the DNA double helix and the addition of nucleotides in the 5' to 3' direction. The tutorial demonstrates how to identify the leading strand, where nucleotides are added in the same direction as helicase movement, and the lagging strand, where nucleotides are added in the opposite direction, forming Okazaki fragments. The video also explores the effect of changing DNA strand orientation on replication.

What is the nature of DNA strands in terms of directionality?

• Perpendicular

• Anti-parallel

• Parallel

• Circular

Which enzyme is responsible for unzipping the DNA double helix?

• RNA primase

• DNA polymerase

• DNA helicase

• DNA ligase

In which direction are new nucleotides added during DNA replication?

• 3' to 5'

• 5' to 3'

• Random

• Both directions

What is the main characteristic of the leading strand during DNA replication?

• It is synthesized in the opposite direction of helicase movement.

• It is synthesized continuously.

• It is synthesized in fragments.

• It does not require a primer.

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

• Crick fragments

• Helicase fragments

• Watson fragments

• Okazaki fragments

Which enzyme is responsible for joining Okazaki fragments?

• DNA helicase

• RNA primase

• DNA ligase

• DNA polymerase

How does changing the orientation of DNA strands affect the identification of leading and lagging strands?

• It makes both strands lagging.

• It makes both strands leading.

• It reverses the roles of the strands.

• It does not affect the identification.

What happens to the leading strand when the orientation of DNA strands is flipped?

• It becomes the lagging strand.

• It stops being synthesized.

• It remains the leading strand.

• It is synthesized in fragments.

In the final review, what direction is the DNA helicase moving when the top strand is identified as the leading strand?

• Right to left

• Upwards

• Downwards

• Left to right

What is the main takeaway from the final review of DNA replication?

• DNA replication is random.

• The orientation of strands does not matter.

• The identification of strands depends on the direction of helicase movement.

• Both strands are synthesized continuously.