Paper I — 2024 December (Supplementary) (2019 Scheme) — Qxi
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Paper I
2024 December (Supplementary) (2019 Scheme) · 100 marks · 180 min
Question
(A): More than 70% of human cancers have a defect in p53 gene
(R): p53 plays a central role in maintaining the integrity of the genome
a) Both A & R are correct and R is the reason for A
b) Both A & R are correct but R is not reason for A
c) A is correct R is incorrect
d) A is incorrect R is correct
Qxi1 marksMCQs
Answer
Correct answer: a) Both A & R are correct and R is the reason for A
Both statements are correct, and R is the reason for A. TP53 is the most commonly mutated gene across human cancers (found in the majority, often cited as >50-70% depending on the series), precisely because p53 is the central “guardian of the genome” — it arrests the cell cycle to allow DNA repair or triggers apoptosis in cells with irreparable DNA damage, preventing propagation of mutations; loss of this checkpoint function is a near-universal step in carcinogenesis, explaining its high mutation frequency.
