UPSC Prelims 2021 · GS Paper I
Question 65: Science and Technology
With reference to recent developments regarding ‘Recombinant Vector Vaccines’, consider the following statements :
- 1.Genetic engineering is applied in the development of these vaccines.
- 2.Bacteria and viruses are used as vectors.
Which of the statements given above is/are correct?
AnswerUPSC’s answer is (c).
Recombinant vector vaccines use a harmless virus or bacterium as a carrier, or vector, to deliver the gene for a target pathogen's antigen into the body. Cells then make the antigen and trigger immunity. Building one requires genetic engineering to insert the foreign gene into the vector. Several Covid-19 vaccines, such as those that use adenovirus vectors, work this way. Remember: engineered virus or bacterium as a delivery vehicle.
- 1. The foreign gene is inserted into the vector by genetic engineering.
- 2. Harmless viruses and bacteria are used as vectors.
How you could have got this
- If you were sure statement 1 is correct, (b) and (d) go: each of them leaves 1 out.
What you needed to know: The foreign gene is inserted into the vector by genetic engineering.
- Then, if you were sure statement 2 is correct, (a) goes: it leaves 2 out.
What you needed to know: Harmless viruses and bacteria are used as vectors.
Only (c) is left. This one needs every statement.
Which options go is worked out from UPSC’s key and the options, not by a model.
Why each option is right or wrong
- (a) Wrong: statement 2 is also correct.
- (b) Wrong: statement 1 is also correct.
- (c) Right: genetic engineering is used, and bacteria and viruses serve as vectors.
- (d) Wrong: both statements are correct.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2021, General Studies Paper I, Series A. The paper on upsc.gov.in.