What is meant by the term biopesticide? Name and explain the mode of action of a popular biopesticide.
Biopesticide is a pesticide which is
(i) Not chemical in nature.
(ii) More specific in action against the pest.
(iii) Safer for environment than chemical pesticides.
A popularly known bio-pesticide is Bt toxin, which is produced by a bacterium called Bacillus thuringiensis. Bt toxin gene has been cloned from this bacterium and expressed in plants. Bt toxin protein when ingested by the insect, gets converted to its active form due to the alkaline pH of the gut.
The activated toxin binds to the surface of midgut epithelial cells and create pores that causes swelling and lysis of the cell and eventually kills the insect.
Name the five key tools for accomplishing the tasks of recombinant DNA technology. Also mention the functions of each tool.
The key tools for accomplishing the tasks of recombinant DNA technology with their functions are mentioned below
(i) Restriction endonucleases for cutting the desired DNA at desired places.
(ii) Gel electrophoresis for separating the desired DNA fragments.
(iii) Ligase enzyme for creating recombinant DNA molecule.
(iv) DNA delivery system like electroporation, microinjection, gene gun method, etc.
(v) Competant host (usually bacteria/yeast) to take up the recombinant DNA.