Genetically modified Bt. Brinjal is developed for
- (a)Drought Resistance
- (b)Insect Resistance
- (c)Bacterial Resistance
- (d)Fungal Resistance
Correct — B, Insect Resistance. Bt brinjal is engineered to carry the cry1Ac gene from the soil bacterium Bacillus thuringiensis (Bt). This gene makes the plant produce a Bt toxin/Cry protein that is lethal to the Brinjal Shoot and Fruit Borer (a lepidopteran insect pest) when the larva ingests it, but is not directly toxic to mammals — giving the plant built-in insect resistance.
- (a)Drought Resistance — The cry1Ac gene targets insect pests, not water stress — Bt brinjal was not engineered for drought tolerance.
- (c)Bacterial Resistance — The inserted gene comes FROM a bacterium (Bacillus thuringiensis) to make an insecticidal protein — it does not confer resistance against bacterial disease.
- (d)Fungal Resistance — The Bt toxin acts against insect larvae, not fungal pathogens — Bt brinjal offers no engineered fungal resistance.
'Bt' crops (Bt cotton, Bt brinjal) are genetically modified to express a cry gene from Bacillus thuringiensis, a soil bacterium that naturally produces crystal (Cry) proteins toxic to specific insect larvae. When a target insect eats the plant tissue, the Cry protein binds to its gut and kills it, so the crop needs less chemical pesticide. This is insect resistance via a bacterial toxin gene — a distinct concept from drought-, disease-, or herbicide-tolerance traits engineered by other means.
The exam trap is assuming 'genetically modified' automatically means drought/climate resilience, since that's a common GM-crop narrative in the news. The specific gene family here (cry, from Bacillus thuringiensis) always signals insect/pest resistance, not abiotic stress tolerance.
- Bt brinjal expresses the cry1Ac gene from Bacillus thuringiensis
- Target pest: Brinjal Shoot and Fruit Borer (Leucinodes orbonalis), a lepidopteran insect
- Purpose: insect/pest resistance, reducing pesticide use — not drought, bacterial, or fungal resistance
- India placed a moratorium on Bt brinjal's commercial release in 2010 over biosafety concerns (it remains commercially unapproved in India, unlike Bt cotton)
- Assuming any GM crop is for drought/climate resilience by default
- Confusing 'Bt' (a bacterium-derived insecticidal gene) with disease/fungal resistance
MPPSC and UPSC typically ask the purpose of a specific GM crop (Bt brinjal, Bt cotton, Golden Rice) or the source organism of the inserted gene — lock the chain: Bt = Bacillus thuringiensis = insect resistance.
A genetically engineered form of brinjal, known as the Bt-brinjal, has been developed. The objective of this is
- (a) To make it pest-resistant
- (b) To improve its taste and nutritive qualities
- (c) To make it drought-resistant
- (d) To make its shelf-life longer
Answer(a) To make it pest-resistant — the Bt (cry1Ac) gene protects against the Shoot and Fruit Borer.
Same fact tested directly — the purpose of Bt brinjal's genetic modification is insect/pest resistance.
- practice — not a real PYQ
The cry1Ac gene used in Bt crops such as Bt cotton and Bt brinjal is originally derived from:
- (a)A soil fungus
- (b)A soil bacterium, Bacillus thuringiensis
- (c)A virus
- (d)A marine alga
Answer(b) A soil bacterium, Bacillus thuringiensis — the source of the insecticidal Cry protein genes.
- practice — not a real PYQ
Which of the following is India's only commercially cultivated genetically modified (Bt) crop?
- (a)Bt brinjal
- (b)Bt cotton
- (c)Bt rice
- (d)Bt mustard
Answer(b) Bt cotton — commercially approved and grown in India; Bt brinjal remains under moratorium.