Now a days it is possible to detect the mutated gene causing cancer by allowing radioactive probe to hybridise its complementary DNA in a clone of cells, followed by its detection using autoradiography because : (NEET 2021)
Answer: (A) mutated gene does not appear on a Photographic film as the probe has no complementarity with it. Answer: (A) mutated gene does not appear on a Photographic film as the probe has no complementarity with it Solution: A radioactively tagged probe is designed to base-pair with the normal gene sequence.
- A.mutated gene does not appear on a Photographic film as the probe has no complementarity with it✓
- B.mutated gene does not appear on Photographic film as the probe has complementarity with it
- C.mutated gene partially appears on a photographic film
- D.mutated gene completely and clearly appears on a photographic film.
Correct Answer
(A) mutated gene does not appear on a Photographic film as the probe has no complementarity with it
Solution & Explanation
Answer: (A) mutated gene does not appear on a Photographic film as the probe has no complementarity with it Solution: A radioactively tagged probe is designed to base-pair with the normal gene sequence. In a clone of cells carrying the mutated gene, the probe cannot hybridise because it lacks complementarity with the altered sequence, so that clone produces no signal on the autoradiograph (photographic film). NCERT Reference: Ch 10, p.183, line 18 — "mutated gene will hence not appear on the photographic film, because the probe will not have complementarity with the mutated gene"