The Question is from neet-zoology human-welfare cancer, and it was created by the author A SUBRAMANYAM

Question

Retinoblastoma, a childhood cancer of the eye, is primarily caused by a mutation in which gene, and how does this mutation contribute to cancer development?

A SUBRAMANYAM · Accepted Answer

## CORE INFORMATION
✓ **Answer**: B
## CONCEPT FRAMEWORK
 **Primary Concept**: Retinoblastoma and tumor suppressor genes
 **Related Topics**: Cancer genetics, cell cycle regulation, oncogenes, tumor suppressor genes
 **Prerequisites**: Understanding of gene mutations, cell cycle control, and cancer development.
## SOLUTION PATHWAY
**Given Information**:
  Retinoblastoma is a childhood eye cancer.
  The question asks about the gene primarily involved and the type of mutation.
**Method & Steps**:
 1. Identify the key gene involved in Retinoblastoma.
  Reasoning: Retinoblastoma is a classic example of a cancer caused by inactivation of a tumor suppressor gene.
  Formula/Rule:  None directly applicable; this is a conceptual understanding question.
 2. Determine the type of mutation and its effect on cell cycle regulation.
  Working: The RB gene (retinoblastoma gene) is a crucial tumor suppressor gene that regulates the cell cycle.  Loss-of-function mutations in RB disrupt its ability to inhibit cell cycle progression, leading to uncontrolled cell growth and cancer development.
  Key Point: Tumor suppressor genes normally prevent uncontrolled cell growth.  Loss-of-function mutations in these genes remove this brake on cell division.
 3. Evaluate the other options.
  Result: Option B correctly identifies the RB gene and the type of mutation (loss-of-function) that leads to retinoblastoma.
  Verification:  The explanation aligns with established knowledge of retinoblastoma genetics.
 ## OPTION ANALYSIS
A :x: p53 is a tumor suppressor gene, but its role in retinoblastoma is secondary to RB.  While p53 mutations can contribute to cancer, they are not the primary cause of retinoblastoma. Gain-of-function mutations in p53 are rare and often don't directly promote DNA repair.
B ✓: Correctly identifies the RB gene and the loss-of-function mutation mechanism in retinoblastoma.
 C :x: BRCA1 is involved in DNA repair, and its loss-of-function mutations increase cancer risk, but it's not the primary gene implicated in retinoblastoma.
D :x: RAS is an oncogene; gain-of-function mutations activate it, promoting cell growth and inhibiting apoptosis.  This is the opposite of what happens in retinoblastoma, which involves a tumor suppressor gene.
 ## LEARNING AIDS
 **Common Mistakes**:
  1.Confusing oncogenes (gain-of-function mutations) with tumor suppressor genes (loss-of-function mutations): Understanding the difference between these gene types is crucial for comprehending cancer development.
  2.Overlooking the importance of loss-of-function mutations in tumor suppressor genes:  These mutations are as significant as gain-of-function mutations in oncogenes in driving cancer.
 **Quick Tips**:
  1.Remember that retinoblastoma is associated with the RB gene, a key regulator of the cell cycle.
  2.Loss-of-function mutations in tumor suppressor genes generally lead to uncontrolled cell growth and cancer.

A SUBRAMANYAM · Answer

p53 gene; Gain of function mutation promotes DNA repair.

A SUBRAMANYAM · Answer

The correct Option is "RB gene; Loss of function mutation leads to uncontrolled cell cycle progression."

A SUBRAMANYAM · Answer

BRCA1 gene; Loss of function mutation impairs DNA damage repair.

A SUBRAMANYAM · Answer

RAS gene; Gain of function mutation inhibits apoptosis.

NEET Zoology Biology and Human Welfare Cancer MCQs

Select Topic

Question Tags

Question Tags

Question Tags

Question Tags

Question Tags

Question Tags

Question Tags

Question Tags

Question Tags

Question Tags

NEET Subjects

Our Bots

Company