Govt. Exams
Entrance Exams
Agrobacterium tumefaciens naturally transfers the T-DNA region from its Ti (Tumor-inducing) plasmid into plant cell chromosomes, making it an excellent biological vector for plant genetic engineering.
PCR amplifies specific DNA segments exponentially in cycles of heating and cooling, creating millions of copies without requiring bacterial cells or cloning vectors.
The Protospacer Adjacent Motif (PAM) is a 2-6 nucleotide sequence immediately next to the target site that is essential for Cas9 to recognize and cleave the DNA.
Off-target effects occur when Cas9 cuts at genomic sites that are similar but not identical to the intended target sequence. This can cause undesired mutations and is a significant concern in therapeutic applications.
The sgRNA is a synthetic RNA molecule that guides the Cas9 endonuclease to the specific target DNA sequence through complementary base pairing, ensuring precise gene editing at the desired location.
Gene gun can deliver multiple genes at once through particle bombardment. While Agrobacterium can be used for multiple genes, it's typically better for single or limited gene transfers. Gene gun offers better efficiency for multi-gene introduction.
Horizontal gene transfer of antibiotic resistance genes from GM organisms to pathogenic bacteria is a major ecological and health concern. This has led to development of alternative marker systems and increased scrutiny by regulatory bodies.
Dideoxynucleotides (ddNTPs) lack the hydroxyl group (-OH) at the 3' carbon of the sugar, preventing further DNA chain elongation. This terminates DNA synthesis and is fundamental to Sanger sequencing.
Bt Cotton was first commercialized in Gujarat in 2002 after receiving GEAC approval. It has since become one of the most widely cultivated GM crops in India.
Bt Brinjal contains a gene from Bacillus thuringiensis that produces Cry1Ac toxin, which is specifically toxic to the Brinjal Fruit and Shoot Borer (BFSB), a major pest affecting brinjal cultivation in India.
