Semi conservative replication

Question 1

What is the structure of DNA?

Answer 1

A long molecule consisting of two strands

Each strand is composed of a sequence of nucleotides.

Question 2

What are the three models of DNA replication?

Answer 2

• Conservative
• Dispersive
• Semi-conservative

The focus is on the end products of DNA replication rather than the mechanism itself.

Question 3

In conservative replication, what happens to the original DNA molecule?

Answer 3

It remains intact and serves as a template for a new DNA molecule

The result is two complete DNA molecules: one parental (old) and one entirely new.

Question 4

Describe the outcome of dispersive replication.

Answer 4

DNA strands consist of segments of old and new DNA intermixed

Each newly formed DNA double helix contains both old DNA (yellow) and new DNA (blue) scattered throughout.

Question 5

What does semi-conservative replication produce?

Answer 5

Two DNA molecules, each with one old strand and one new strand

Each new double helix is composed of an old strand (yellow) paired with a new strand (blue).

Question 6

Who conducted the Meselson-Stahl experiment?

Answer 6

Matthew Meselson and Franklin Stahl

The experiment provided evidence supporting the semi-conservative model of DNA replication.

Question 7

What was the purpose of using isotopes of nitrogen in the Meselson-Stahl experiment?

Answer 7

To differentiate between old and new DNA strands

This ultimately confirmed the semi-conservative nature of DNA replication.

Question 8

Why is the understanding of DNA replication important?

Answer 8

• Genetics
• Molecular biology
• Biotechnological applications

Knowledge of replication mechanisms impacts genetic fidelity, evolution, and methodologies in cloning and genetic engineering.