Question:

Study the following statements regarding Bt toxins produced by bacterium Bacillus thuringiensis and select the correct one.

Updated On: Jul 7, 2022

Most strains of Bacillus thuringiensis produce proteins that kill certain insects such as lepidopterans, cqleopterans and dipterans
Bt toxin proteins do not kill the bacteria themselves because the toxin proteins occur in an inactive form called protoxins
When an insect ingests the inactive Bt toxin, it is converted to an active form of toxin due to alkaline $pH$ of the gut which solubilises the protein toxin crystals
All of these

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The Correct Option is D

Solution and Explanation

Soil bacterium, Bacillus thuringiensis (Bt) produces proteins that kill certain insects like lepidopterans (tobacco budworm, armyworm), coleopterans (beetles) and dipterans (flies, mosquitoes). Bacillus thuringiensis forms some intracellular protein crystals. These crystals contain a toxic insecticidal protein. The Bt toxin protein exists as inactive toxin and is converted into an active form due to the alkaline $pH$ of the alimentary canal that solubilises the crystals. The activated toxin binds to the surface of midgut epithelial cells and create pores which cause cell swelling and lysis and finally cause death of the insect.

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Notes on Applications of Biotechnology

Concepts Used:

Applications of Biotechnology

Biotechnology is the technology that utilizes biological systems, living organisms, or parts of this to develop or create different products.

For example, brewing and baking bread fall within the concept of biotechnology (use of yeast (= living organism) to produce the desired product).

Agriculture

Alternative to conventional farming: A possible solution is the use of genetically modified crops which is an alternative path to conventional farming.

Medicine

In the area of healthcare, recombinant DNA technological processes have made an immense impact which enables the mass production of safe and more effective therapeutic drugs.

Gene Therapy

A collection of methods that allows the correction of a gene defect that has been diagnosed in a child/embryo is called Gene Therapy.

CRISPR technology

For editing genomes, CRISPR is a simple yet powerful tool which allows researchers to easily alter DNA sequences and modify gene function.