Kdr gene in housefly is present in chromosome no.

Answer: Option A

Kdr gene in houseflies is present in chromosome no. 3.
Knockdown resistance (kdr) is a well-characterized mechanism of resistance to pyrethroid insecticides in many insect species and is caused by point mutations of the pyrethroid target site the para-type sodium channel.
The term knockdown resistance (kdr) describes cases in which insects have become resistant to DDT or pyrethroids through a reduced sensitivity in the nervous system.