Bt Toxin

Q. Bt toxin kills insects by

1. inhibiting protein synthesis
2. generating excessive heat
3. creating pores in the midgut epithelial cells, leading to cell swelling and lysis
4. obstructing a biosynthetic pathway

Q. Bt toxin kills certain insects such as lepidopterans (tobacco budworm, armyworm), coleopterans (beetles) and dipterans (flies, mosquitoes). But, actually, the Bt toxin protein exists as inactive protoxins. What makes the activation of protoxin to active toxin in bollworm?

1. Acidic pH of stomach
2. Body temperature
3. Moist surface of midgut
4. Alkaline pH of gut

Q. In Bt cotton, the Bt toxin present in plant tissue as protoxin is converted into active toxin due to:

1. presence of conversion factors in the insect gut
2. alkaline pH of the insect gut
3. acidic pH of the insect gut
4. the action of gut microorganisms

Q. Toxin produced by Bt cotton plant gets activated in:

1. Mouth of insect by acidic pH
2. Midgut of insect by alkaline pH
3. Leaves of plant by acidic pH
4. Stem of plant by alkaline pH

Q. In case of Bacillus thuringiensis, Bacillus itself is not killed by the toxic protein crystals produced by it because

1. Bt toxin protein is not produced in the bacillus
2. Bt toxin protein is produced in very less amount in the bacillus
3. Bt toxin exists as inactive toxin
4. Bt toxin can’t cause any damage to bacillus.

Q. Which genes are incorporated in cotton to protect from cotton bollworms?

1. cryIAc and cryIAb
2. cryIIAc and cryIIAb
3. cryIAc and cryIIAb
4. cryIIAc and cryIAb

Q. Bt protein is made as an inactive protein.

1. True
2. False

Q. Cry genes introduced in a plant will not be affective against

1. coleopterans
2. Lepidoptera
3. hymenoptera
4. rodents

Q. Cry genes introduced in a plant will not be affective against

1. coleopterans
2. Lepidoptera
3. hymenoptera
4. rodents

Q. The Cry protein targets which part of the insect?

1. Digestive system
2. Nervous system
3. Circulatory system
4. Reproductive system

Q. The prefix “Bt” in Bt cotton means

1. “Barium treated” cotton seeds
2. “Bigger thread” variety of cotton with better tensile strength
3. Carrying an endotoxin gene from Bacillus thuringiensis
4. Produced by “biotechnology” using restriction enzymes and ligases