Exams › NEET › Biology

The bacterium Bacillus thuringiensis is widely used in contemporary biology as insecticide. Bacillus thuringiensis (also known as Bt) is a Gram-positive, soil dwelling bacterium of the genus Bacillus. Bacillus thuringiensis produces a parasporal insecticidal crystal protein.

1. Gram positive bacteria have a thick peptidoglycan layer and no outer lipid membrane whilst Gram negative bacteria have a thin peptidoglycan layer and have an outer lipid membrane.
2. Cry endotoxin obtained from Bacillus thuringiensis are effective against bollworms. A bollworm is a common term for any larva of a moth that attacks the fruiting bodies of certain crops, especially cotton.
3. The term Green revolution refers to the very substantial increase in yield obtained by breeding high yielding varieties of crops, under intensive application of fertilizers, irrigation and pesticides. The world wide increase, in productivity has come to be known as the ‘Green Revolution’ for which Dr. Borlaug won the Noble Peace Prize in 1970.
4. Bt cotton, a transgenic crop variety has been introduced in India. The Bt cotton variety contains a foreign gene obtained from Bacillus thuringiensis. This bacterial gene protects cotton from the bollworm, a major pest of cotton.

Correct answer: Cry endotoxin obtained from Bacillus thuringiensis are effective against bollworms. A bollworm is a common term for any larva of a moth that attacks the fruiting bodies of certain crops, especially cotton.

Solution

Bt produces Cry proteins, which are toxic to certain insect larvae. Bollworms are among the key susceptible pests, especially in cotton, so the option describing Cry endotoxin against bollworms is correct.

Related NEET Biology questions

• Which of the following is true for Golden rice?
• What triggers activation of protoxin to active Bt toxin of Bacillus thuringiensis in boll worm?
• The crops engineered for glyphosate are resistant/tolerant to:
• The genetic defect - Adenosine deaminase (ADA) deficiency may be cured permanently by:
• In transgenics, expression of transgene in target tissue is determined by
• An improved variety of transgenic basmati rice

⚔️ Practice NEET Biology free + battle 1v1 →