UPSC Prelims 2019— Question 43

This question tests the concept of Synthetic Biology and DNA Technology. The key principle is that Synthetic DNA and laboratory replication, as well as cell culture and division, are established techniques. The statement about creating a functional chromosome simply by joining DNA segments from different species is the incorrect formulation in the question. The correct answer marked for this question is option A. The distinction matters because UPSC often combines a familiar factual statement with one carefully qualified or overly broad statement. A reliable way to solve such questions is to identify the governing concept first and then test every statement against its precise wording rather than relying on general familiarity. Because the question asks for the statement or option that is not correct, the task is to identify the choice that conflicts with the established position; the other choices must be assessed as plausible or correct within the wording of the question. Option A — Functional chromosomes can be created by joining segments of DNA taken from cells of different species.: This is the correct choice. It is consistent with the governing fact or with the valid combination identified above. The important point is not merely that the wording appears familiar, but that it matches the specific scope of the question and does not add an unsupported condition. Option B — Pieces of artificial functional DNA can be created in laboratories.: This is not the correct choice. It either excludes a statement that must be included, includes a statement that is inaccurate, or identifies a different institution, process, location, technology or historical development from the one tested. Its wording should therefore be rejected when checked against the core principle described above. Option C — A piece of DNA taken out from an animal cell can be made to replicate outside a living cell in a laboratory.: This is not the correct choice. It either excludes a statement that must be included, includes a statement that is inaccurate, or identifies a different institution, process, location, technology or historical development from the one tested. Its wording should therefore be rejected when checked against the core principle described above. Option D — Cells taken out from plants and animals can be made to undergo cell division in laboratory petri dishes.: This is not the correct choice. It either excludes a statement that must be included, includes a statement that is inaccurate, or identifies a different institution, process, location, technology or historical development from the one tested. Its wording should therefore be rejected when checked against the core principle described above. In exam terms, the safest approach is to break the question into its smallest factual units. Where statements are combined, verify each statement independently and then compare the resulting combination with the four codes. Where the question asks for a single institution, event, technology or location, distinguish the exact term from closely related alternatives. This prevents elimination based only on familiarity and is especially useful in UPSC questions where one small qualifier can change the correctness of an otherwise plausible statement. Thus, after checking the individual propositions and the scope of the alternatives, option A is the answer.