Question

In Bt. Cotton, the Bt. The toxin present in plant tissue as pro-toxin is converted into active toxin due to
(A) Action of gut microorganisms.
(B) Presence of conversion factors in the insect gut.
(C) Alkaline pH of the insect gut.
(D) Acidic pH of the insect gut.

Answer 1

Hint: Biotechnology is an area of biology in which it involves the use of living systems and organisms to develop or make products. Genetic modification is a part of this branch where genetically modified organisms (GMO) are developed. Some of its applications are used in agriculture. They developed pest-resistant plants, which could decrease the amount of pesticide by using Bt. Toxin.

Complete answer:
Bt. The toxin is produced by a bacterium called Bacillus thuringiensis. In short, it is written as Bt. It has been cloned from the bacteria and been expressed in plants to produce resistance to insects without the need for insecticide. It is also known as bio-pesticide.
Example: Bt. Cotton, Bt. Corn, Bt. rice etc.
Bt. Cotton has some strains of Bacillus thuringiensis that produce proteins that kill certain insects such as lepidopterans, coleopterans and dipterans. B. thuringiensis forms protein crystals during a particular phase of growth. These crystals contain a toxic insecticidal protein. The Bt. Toxin protein exists as inactive pro-toxins but once it enters the insect body the inactive toxin converted into an active form of toxin due to alkaline pH of the gut which solubilizes the crystals. The activated toxin binds to the surface of the midgut epithelial cells and creates pores that cause cell swelling and lysis and eventually cause the death of the insect.

So, (C) is the correct answer.

Note:
In above we detailed the application of biotechnology in different ways and got to know about the methods to develop new organisms or products by applying biotechnology which helps us in development of genetically modified organisms. This application has enhanced the knowledge of genetics and many more new technologies are coming in the future.