The Bt gene used in Bt cotton is obtained from which organism?
- A.A virus
- B.A bacterium
- C.A fungus
- D.An alga
Correct answer
Explanation
The correct answer is B, a bacterium. The cry genes of Bt cotton come from Bacillus thuringiensis, a soil bacterium that forms crystal protein during sporulation; the protein is inactive as eaten but becomes a toxin in the alkaline gut of the bollworm, which is why the plant resists the pest. Option A is wrong because viral genes are used for other purposes, such as the coat protein approach to virus resistance, not for Bt. Option C is wrong because fungi are used as biopesticides in their own right, as Trichoderma is against soil borne disease, but the cry gene is not fungal. Option D is wrong because algae such as Anabaena serve as biofertilisers in paddy fields rather than as a source of insecticidal genes. Remember the full name Bacillus thuringiensis behind the two letters Bt.
Read the full article: Biotechnology in Agriculture and Health: Notes and PYQs
Practice Questions
View allWhich genetically modified crop is approved for commercial cultivation in India?
- A.Bt brinjal
- B.Golden rice
- C.Bt cotton
- D.GM soybean
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Approved in 2002, it is the only genetically modified crop cleared for commercial cultivation by Indian farmers, and it is grown for fibre rather than as food.
Read the full explanation →The polymerase chain reaction, used to multiply a chosen segment of DNA, was invented by:
- A.Kary Mullis
- B.Alec Jeffreys
- C.Herbert Boyer
- D.Ian Wilmut
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He devised the polymerase chain reaction, which copies a selected stretch of DNA millions of times through repeated cycles of heating and cooling, using the heat resistant Taq polymerase, and he received the Nobel Prize in Chemistry for it.
Read the full explanation →Golden rice was developed to address the deficiency of which nutrient?
- A.Iron
- B.Vitamin A
- C.Iodine
- D.Vitamin D
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Golden rice was engineered to make beta carotene, the precursor from which the body forms vitamin A, in the edible part of the grain, and the pigment gives the rice its golden colour; the aim was to reduce night blindness among populations living mainly on rice.
Read the full explanation →Which body is the apex authority for approving the environmental release of genetically engineered organisms in India?
- A.Review Committee on Genetic Manipulation
- B.Genetic Engineering Appraisal Committee
- C.National Biodiversity Authority
- D.Indian Council of Agricultural Research
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Working under the Ministry of Environment, Forest and Climate Change, it is the apex committee under the rules of 1989 framed under the Environment (Protection) Act, 1986, and no genetically engineered organism may be released into the environment or used on a large scale without its clearance.
Read the full explanation →Which of the following branches of botany deals with the development of improved plant varieties?
- A.Plant embryology
- B.Plant breeding
- C.Plant biochemistry
- D.Plant anatomy
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Plant breeding is the deliberate improvement of crops by choosing parents with desirable characters, crossing them, selecting among the progeny and multiplying the best lines; the high yielding wheat and rice varieties of the Green Revolution came from it, and modern breeding is often combined with tissue culture and marker…
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