Explanation:

Insect-resistant cotton plants have been genetically engineered by inserting a gene from a bacterium.The cotton incorporated the cry1Ac gene from the soil bacterium Bacillus thuringiensis (Bt), making the cotton toxic to bollworms.The genetically modified crop is called Bt cotton as it contains Bt toxin genes. Bt cotton is the genetically modified (GM) crop that has been approved for commercial cultivation in 2002 by the Government of India

Bt brinjal is the first transgenic crop commercially available in India.  Genetically modified plants are produced by modifying the DNA of a plant, thus giving it new characteristics.Bt cotton, Bt brinjal, golden rice are some examples of transgenic crops.

In tobacco, the gene silencing method is applied using RNAi.