The cultivation of Bt cotton has been much in the news. What does the prefix "Bt" in Bt cotton signify?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Cotton containing a gene derived from Bacillus thuringiensis that produces toxin
“Bt” is short for Bacillus thuringiensis, a soil bacterium. Some strains of this bacterium make a protein that is toxic to certain insects. The gene for this toxin was taken from the bacterium and put into cotton plants. Bt cotton makes the toxin itself, so bollworms that feed on it die. The farmer then needs far less insecticide, which is why Bt cotton is called a bio-pesticide crop. The other options are not what “Bt” stands for.
NCERT Extract:
Biotechnological Applications in Agriculture – “… Some of the applications of biotechnology in agriculture that you will study in detail are the production of pest resistant plants, which could decrease the amount of pesticide used. Bt toxin is produced by a bacterium called Bacillus thuringiensis (Bt for short). Bt toxin gene has been cloned from the bacteria and been expressed in plants to provide resistance to insects without the need for insecticides; in effect created a bio-pesticide. Examples are Bt cotton, Bt corn, rice, tomato, potato and soyabean etc.”