NEET Botany

Cry proteins from Bacillus thuringiensis work by binding to specific receptors in the alkaline midgut of susceptible insects, forming pores that lead to cell lysis and death. This is the well-established mechanism of Bt toxin action, making it selective for certain insect orders.

The GEAC under the Ministry of Environment, Forest and Climate Change approves GM crops in India after safety and efficacy assessment.

MAS uses molecular markers (DNA sequences) to identify and select plants carrying desired genes without waiting for phenotypic expression.

T-DNA (Transfer DNA) is the specific segment of the Ti plasmid that integrates into the plant genome during Agrobacterium-mediated transformation.

Somaclones are plants regenerated from somatic cells via tissue culture, genetically identical to the parent plant unless mutations occur.

A low auxin to high cytokinin ratio promotes shoot formation, while the opposite (high auxin : low cytokinin) promotes root formation.

Callus is undifferentiated plant tissue used in micropropagation and plant regeneration through somatic embryogenesis or organogenesis.

Golden Rice contains genes for beta-carotene production, making it rich in Vitamin A, addressing nutritional deficiency in rice-consuming populations.

Both microprojectile bombardment (gene gun) and electroporation are direct DNA delivery methods that don't require a biological vector.

As of 2024-25, only Bt Cotton is commercially cultivated in India. Bt Brinjal has regulatory issues, and Bt Rice/Maize are not approved yet.