UPSC Prelims 2017 · GS Paper I
Question 31: Science and Technology
Consider the following statements :
- 1.In tropical regions, Zika virus disease is transmitted by the same mosquito that transmits dengue.
- 2.Sexual transmission of Zika virus disease is possible.
Which of the statements given above is/are correct ?
AnswerUPSC’s answer is (c).
Zika virus is spread mainly by Aedes mosquitoes, chiefly Aedes aegypti, the same day-biting mosquito that carries dengue and chikungunya in tropical regions, so Statement 1 is right. Zika can also spread through sexual contact, and from mother to foetus, so Statement 2 is right. Infection in pregnancy has been linked to microcephaly in newborns. Remember: Zika, dengue and chikungunya share the Aedes vector, and Zika has a sexual route too.
- 1. Aedes aegypti transmits both Zika and dengue.
- 2. Zika can be transmitted sexually.
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: Aedes aegypti transmits both Zika and dengue.
- Then, if you were sure statement 2 is correct, (a) goes: it leaves 2 out.
What you needed to know: Zika can be transmitted sexually.
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) Incomplete: sexual transmission (2) is also possible.
- (b) Incomplete: the shared Aedes mosquito (1) is also correct.
- (c) Right: both statements are correct.
- (d) Wrong: both statements are true.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2017, General Studies Paper I, Series A. The paper on upsc.gov.in.