The polymerase chain reaction, used to multiply a chosen segment of DNA, was invented by:

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.

The correct answer is C, Bt cotton. 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. Option A is wrong because Bt brinjal, though developed and field tested, was placed under a moratorium in 2010 and has not been released. Option B is wrong because golden rice, engineered to make beta carotene in the grain, has never been approved for cultivation in India. Option D is wrong because genetically modified soybean is not approved for cultivation here, although imported soybean oil has been permitted at times. Statement based questions often claim that India grows several GM food crops, which is false; keep Bt cotton as the single approved crop and note the brinjal moratorium.

The correct answer is B, vitamin A. 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. Option A is wrong because iron deficiency is addressed by biofortified varieties of pearl millet and wheat and by fortified foods, not by golden rice. Option C is wrong because iodine deficiency is tackled by iodised salt, a public health measure that needs no engineering of the crop. Option D is wrong because vitamin D is obtained largely from sunlight and from fortified milk. Golden rice is the standard example of biofortification by genetic engineering.

The correct answer is B, the Genetic Engineering Appraisal Committee. 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. Option A is wrong because the Review Committee on Genetic Manipulation, under the Department of Biotechnology, monitors research and small scale trials rather than commercial release. Option C is wrong because the National Biodiversity Authority, at Chennai, deals with access to biological resources and benefit sharing under the Act of 2002. Option D is wrong because ICAR conducts agricultural research and coordinates trials but grants no biosafety approval. Learn the pair as RCGM for research and GEAC for release.

The correct answer is B, plant breeding. 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 assisted selection. Option A is wrong because plant embryology studies the development of the embryo and seed, which is descriptive rather than an improvement programme. Option C is wrong because plant biochemistry studies the chemical reactions inside the plant, such as photosynthesis and secondary metabolites. Option D is wrong because plant anatomy studies internal structure and tissues under the microscope. Breeding works with genes already present in related plants, while genetic engineering can bring a gene from any organism.