Explain how semi-conservative replication ensures genetic continuity during cell division, and what would be the consequence if replication was fully conservative?
Understand the Problem
The question asks to explain the mechanism of semi-conservative DNA replication and its role in maintaining genetic information during cell division. It also asks to consider what would happen if DNA replication followed a fully conservative model instead.
Answer
Genetic continuity is ensured through semi-conservative replication, where each new DNA molecule contains one original and one new strand. Fully conservative replication could cause genetic variations.
Semi-conservative replication ensures genetic continuity by using each strand of the original DNA molecule as a template for a new strand, resulting in two DNA molecules, each with one original and one new strand. If replication were fully conservative, the original DNA would remain intact, while a completely new DNA double helix would be created, potentially leading to genetic variations and inconsistencies during cell division.
Answer for screen readers
Semi-conservative replication ensures genetic continuity by using each strand of the original DNA molecule as a template for a new strand, resulting in two DNA molecules, each with one original and one new strand. If replication were fully conservative, the original DNA would remain intact, while a completely new DNA double helix would be created, potentially leading to genetic variations and inconsistencies during cell division.
More Information
The Meselson-Stahl experiment in 1958 proved that DNA replication is semi-conservative. They used isotopes of nitrogen to distinguish between old and new DNA strands after replication.
Tips
A common mistake is confusing semi-conservative replication with conservative or dispersive replication. Semi-conservative replication results in each new DNA molecule having one original and one new strand. Conservative replication would create one entirely new DNA molecule and leave the original intact. Dispersive replication would result in both new molecules having segments of both original and new DNA interspersed.
Sources
- 7.2: Semi-Conservative DNA Replication - Biology LibreTexts - bio.libretexts.org
- Mode of DNA replication: Meselson-Stahl experiment - Khan Academy - khanacademy.org
- What is the importance of semiconservative replication of DNA? - quora.com
AI-generated content may contain errors. Please verify critical information
