Biotechnology and Health — Quick Revision

A last-week revision sheet for biotechnology. Prelims here rewards knowing which body, which gene, which platform.

The rDNA Toolkit

Tool	Role
Restriction enzyme	Cuts DNA at specific sequences (“molecular scissors”)
DNA ligase	Joins DNA fragments (“molecular glue”)
Vector (plasmid, virus, Agrobacterium)	Carries the gene into the host
Host (E. coli, yeast, plant cell)	Copies the gene and expresses the protein
PCR	Amplifies a DNA segment millions of times
Gel electrophoresis	Separates DNA fragments by size

Item	Fact
Bt cotton	cry genes from Bacillus thuringiensis; approved 2002
Bt brinjal	GEAC clearance 2009; moratorium February 2010
GM mustard DMH-11	barnase–barstar + bar; environmental release October 2022; Supreme Court split verdict July 2024
Legal base	1989 Rules under the Environment (Protection) Act, 1986
GEAC	MoEFCC — environmental release
RCGM	DBT — research and contained trials
IBSC	Each institution — first-level oversight
Cartagena Protocol	Adopted 2000, in force 2003 — transboundary movement of living modified organisms

Category	Change	Foreign DNA?	India
SDN-1	Cut + natural repair	No	Exempt (2022)
SDN-2	Cut + template-guided repair	No	Exempt (2022)
SDN-3	Gene insertion	Yes	Regulated as GM

Platform	Indian or well-known example
Live attenuated	Oral polio vaccine, BCG, MMR
Inactivated	Covaxin; injectable polio vaccine
Protein subunit	Corbevax; hepatitis B
Toxoid	Tetanus, diphtheria
Viral vector	Covishield
mRNA	Pfizer–BioNTech, Moderna
DNA	ZyCoV-D (2021, first human DNA vaccine)

High-yield facts

Bt toxin: protoxin, activated in the alkaline insect gut.
Nobel Prizes: iPSCs 2012 (Yamanaka); CRISPR 2020 (Charpentier, Doudna); mRNA base modification 2023 (Karikó, Weissman).
NexCAR19 — first indigenous CAR-T therapy, approved 2023.
BioE3 Policy — August 2024.
National Sickle Cell Anaemia Elimination Mission — launched July 2023, target 2047.
Genome-edited rice varieties (DRR Dhan 100 Kamala, Pusa DST Rice 1) — May 2025.

Watch these

GEAC is under MoEFCC, not the DBT.
Genome-edited (SDN-1/2) is not “GM” under Indian rules.
mRNA vaccines do not alter DNA.
Pink bollworm has developed resistance to Bt cotton — “Bt cotton ended pest attacks” is false.