Q.The common mosquito vector responsible for transmitting both dengue and chikungunya viruses is:
(A) Anopheles mosquito
(B) Culex mosquito
(C) Aedes aegypti mosquito
(D) Housefly

Anopheles transmits malaria and Culex transmits filariasis, not dengue/chikungunya.

Aedes aegypti is a day-biting mosquito that breeds preferentially in small collections of clean, stagnant water (flowerpots, discarded tyres, coolers), and it is the vector for both the dengue virus and the chikungunya virus. This shared vector is exactly why both diseases are covered together in this chapter and share the same prevention strategy — eliminating stagnant water breeding sites.

The other options name mosquitoes responsible for different diseases discussed elsewhere in this chapter: Anopheles (option A) transmits malaria, and Culex (option B) transmits filariasis. The housefly (option D) is not a disease vector for either dengue or chikungunya at all.

Memorise this chapter's three distinct mosquito-disease pairings as a fixed set: Anopheles→malaria, Culex→filariasis, Aedes aegypti→dengue and chikungunya — MCQs frequently test exactly this kind of pairing.

Do not pick Anopheles simply because it is the most 'famous' disease-carrying mosquito from earlier study of malaria — each mosquito genus in this chapter transmits a specific, different set of diseases.