What are Cry proteins? Name an organism that produce it. How has man exploited this protein to his benefit?
Cry proteins are Bt toxins (toxin proteins) that are coded by genes named cry. There are different types of these proteins such as cryIAc, cryIIAb, and cryIAb.
Bacillus thuringiensis is the organism that produces Cry proteins.
Man has exploited these proteins by isolating the specific Bt toxin genes from Bacillus thuringiensis and incorporating them into crop plants such as cotton. These proteins are insect-group specific and help control pests — for example, the proteins encoded by genes cryIAc and cryIIAb control cotton bollworms, while cryIAb controls corn borer.
Explanation
This is a direct question from NCERT Biology Class 12, Chapter 10 (Biotechnology and its Applications). The context clearly mentions that Cry proteins are Bt toxins coded by cry genes, produced by Bacillus thuringiensis. The exploitation involves incorporating these genes into crops for pest resistance. The choice of genes depends on the crop and targeted pest, as most Bt toxins are insect-group specific.