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Question #46541
The Question
In the context of cell cycle regulation and oncogenic transformation, which of the following statements is INCORRECT regarding the genetic mutations that lead to malignant neoplasia?
Options
- A.
Activation of cellular oncogenes (c-onc) in somatic cells leads to sporadic malignant neoplasia by overriding cell cycle checkpoints.
- B.
A germline mutation activating a proto-oncogene results in vertical transmission of cancer susceptibility, bypassing the need for an initial environmental trigger in the progeny.
- C.
Proto-oncogenes typically undergo recessive loss-of-function mutations to transform into oncogenes, similar to the inactivation of tumor suppressor genes.
- D.
The loss of contact inhibition in neoplastic cells is a direct phenotypic consequence of the genetic alterations in regulatory genes.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Oncogenes vs Proto-oncogenes|Gene Therapy Germline vs Somatic|DNA Replication
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students frequently confuse the mutational mechanisms of proto-oncogenes and tumor suppressor genes.
The common misconception is assuming all cancer-causing mutations are 'loss of function' because overall cellular control is lost.
However, proto-oncogenes require a 'gain-of-function' (dominant) to become oncogenic, whereas tumor suppressors require a 'loss-of-function' (recessive).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Human Health and Disease - Class 12 |
| Concept | Oncogenes vs Proto-oncogenes |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |