Q.1 Bt cotton is not

(a) a GM plant                                           

(b) insect resistant
(c) a bacterial gene expressing system 

(d) resistant to all pesticides

(d) Bt cotton is a genetically modified plant whose genes have been altered by the manipulations to make it insect resistant through the introduction of Bt toxin gene

Bt toxin is produced by a bacterium called Bacillus thuringiensis (Bt). Bt toxin gene has been cloned from the bacteria which is expressed in plants to provide resistance to insects.

Some strains of Bacillus thuringiensis produce proteins that kills certain insects like lepidopterans (tobacco budworm, armyworm), coleopterans (beetles) and dipterans (flies, mosquitoes).

Bt cotton is made resistant to certain taxa of pests only (as mentioned above). It is quite likely that in future, some other pests may infest these Bt cotton plants.