UPSC Prelims 1996 · General Studies
Question 100: Science and Technology
Which of the following professional(s) are more likely to run the risk of a permanent change in their cell’s DNA? I. Researchers using carbon-14 isotope II. X-ray technician III. Coal miner IV. Dyer and painter Select the correct answer using the codes given below:
AnswerThe answer is (c).
A permanent change in DNA (a mutation) is caused by ionising radiation and by some chemicals. Carbon-14 is radioactive, X-rays are ionising radiation, and many dyes and paints contain chemicals that can cause mutations, so I, II and IV carry the risk. Coal mining mainly brings lung disease from dust (pneumoconiosis), not mainly a change in DNA.
- I. Carbon-14 is radioactive and radiation can damage DNA.
- II. X-rays are ionising radiation and can cause mutations.
- III. Coal dust mainly causes lung disease, not mainly DNA change.
- IV. Chemicals in dyes and paints can cause mutations.
Why each option is right or wrong
- (a) II alone leaves out the radioactive isotope and the dyes.
- (b) Includes the coal miner, whose main risk is lung disease from dust.
- (c) Right: radioactive carbon-14, X-rays and dyes and paints.
- (d) Includes the coal miner and leaves out the X-ray technician, an ionising-radiation risk.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 1996, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.