NEET BIOLOGY

Detailed explanation-1: -Crystal (Cry) proteins made by the bacterium Bacillus thuringiensis (Bt) are pore-forming toxins that specifically target invertebrates (insects and nematodes) and are generally innocuous to mammals. They are widely used as insecticides in agriculture and to control parasitic nematodes.

Detailed explanation-2: -Bacillus thuringiensis (Bt) is a Gram positive, spore-forming bacterium that synthesizes parasporal crystalline inclusions containing Cry and Cyt proteins, some of which are toxic against a wide range of insect orders, nematodes and human-cancer cells.

Detailed explanation-3: -Bacilus thuringiensis forms protein crystals which contain insecticidal protein.

Detailed explanation-4: -A protein crystal typically has dimensions of   0.5 mm and contains about 1015 protein molecules in a periodic array.

Detailed explanation-5: -Protein crystal structures are the result of a human interpretation of electron-density maps that are biased by the very model one is building. It is therefore no surprise that misinterpretations occur.