LIFE SCIENCE

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: -Protein crystallization is the process of formation of a regular array of individual protein molecules stabilized by crystal contacts. If the crystal is sufficiently ordered, it will diffract. Some proteins naturally form crystalline arrays, like aquaporin in the lens of the eye.

Detailed explanation-3: -Bacillus thuringiensis forms proteins which contain insecticidal proteins.

Detailed explanation-4: -Protein crystals grow principally by the classical mechanisms of dislocation growth and growth by two-dimensional nucleation, along with two other less common mechanisms known as normal growth and three-dimensional nucleation (Malkin et al., 1995 ▶; McPherson & Malkin, 2000 ▶).