The Question is from neet-botany , and it was created by the author D VINOD

Question

Imagine a prokaryotic organism with a mutated DNA polymerase III that lacks 3' to 5' exonuclease activity. What would be the MOST LIKELY consequence of this mutation?

D VINOD · Accepted Answer

## CORE INFORMATION
✓ **Answer**: C
## CONCEPT FRAMEWORK
 **Primary Concept**: DNA replication and error correction
 **Related Topics**: DNA polymerase III function, exonuclease activity, mutations
 **Prerequisites**: Understanding of DNA replication, the role of DNA polymerase III, and the function of 3' to 5' exonuclease activity.
## SOLUTION PATHWAY
**Given Information**:
	Prokaryotic organism
	Mutated DNA polymerase III
	Lack of 3' to 5' exonuclease activity
**Method & Steps**:
 1. Understand the role of DNA polymerase III and its 3' to 5' exonuclease activity.
  Reasoning: DNA polymerase III is the main enzyme responsible for DNA replication in prokaryotes.  Its 3' to 5' exonuclease activity is a proofreading function. It allows the polymerase to remove incorrectly incorporated nucleotides during replication.
  Formula/Rule: None directly applicable, but understanding the function is crucial.
 2. Consider the consequence of lacking this proofreading function.
  Working: Without the 3' to 5' exonuclease activity, the DNA polymerase III will not be able to remove incorrectly incorporated nucleotides. This means that errors in replication will persist.
  Key Point:  The 3' to 5' exonuclease activity is crucial for maintaining the fidelity of DNA replication.
 3. Determine the most likely consequence.
  Result: A higher rate of mutations in the replicated DNA is the most likely outcome because errors during replication are not corrected.
  Verification: The other options are less likely. Slower replication is possible, but not the most likely direct consequence. Inability to initiate replication is unlikely as other components of replication would still function. Increased Okazaki fragments are not directly related to proofreading.
## OPTION ANALYSIS
A :x: Slower replication fork movement is a possible indirect consequence, but the primary effect is the accumulation of errors.
B :x: The inability to initiate replication is not directly linked to the 3' to 5' exonuclease activity of DNA polymerase III.
C ✓: A higher rate of mutations is the direct and most likely consequence of losing the proofreading function.
D :x: The number of Okazaki fragments is not directly affected by the 3' to 5' exonuclease activity of DNA polymerase III.
## LEARNING AIDS
 **Common Mistakes**:
  1.Confusing 3' to 5' exonuclease activity with 5' to 3' polymerase activity: Remember that these are distinct functions.
  2.Focusing on other aspects of DNA replication: The question specifically targets the consequence of the missing proofreading function.
 **Quick Tips**:
  1.Remember the role of exonuclease in proofreading.
  2.Connect the lack of proofreading to increased error rates in replication.

D VINOD · Answer

Slower replication fork movement

D VINOD · Answer

Inability to initiate DNA replication

D VINOD · Answer

The correct Option is "A higher rate of mutations in the replicated DNA"

D VINOD · Answer

Increased formation of Okazaki fragments

NEET Botany MCQs

Select Chapter

Question Tags

NEET Subjects

Our Bots

Company