- Genetic engineering is the manipulation of DNA to modify genes, transfer them between organisms, or alter gene expression.
- Because the genetic code is universal, genes from one organism can function in another to produce useful products like human insulin and growth hormone.
- This technology is used to create transgenic organisms and genetically modified crops with improved traits such as disease resistance and better nutrition.
Definitions [2]
Define genetic engineering.
Genetic engineering is the manipulation and transfer of genes from one organism to another organism to create a new DNA called recombinant DNA (rDNA). Genetic engineering is also called recombinant DNA technology.
Definition: DNA Fingerprinting
The technique of identifying an individual by analyzing the unique DNA sequence present in each person, similar to fingerprints, is called DNA fingerprinting.
Key Points
Key Points: Green Revolution
- Green Revolution refers to the collective methods used to obtain maximum agricultural yield from minimum land to overcome food scarcity caused by population explosion.
- Development of high-yielding dwarf varieties of wheat and rice, along with proper use of fertilizers, pesticides, and water management, greatly increased food grain production.
- Dr. Norman Borlaug and Dr. M. S. Swaminathan played key roles in the Green Revolution, supported by research institutes like IARI, New Delhi, and other national agricultural research centers.
Key Points: Animal Husbandry (Livestock) > Animal Breeding
- Meaning — Breeding & raising livestock to increase yield and improve desirable qualities (milk, meat, eggs).
- Inbreeding — Closely related individuals bred for 4–6 generations → increases homozygosity, eliminates harmful genes. Demerit: reduces fertility.
- Outbreeding — Unrelated animals, no common ancestor for 4–6 generations → removes inbreeding depression.
- Types of Outbreeding — Outcrossing (same breed), Crossbreeding (different breeds), Interspecific hybridisation (different species).
- Examples — Hisardale sheep = Bikaneri ewe × Marino ram | Mule = Horse × Donkey.
- Artificial Insemination (AI) — Semen from a superior male → frozen/preserved → injected into the female's genital tract.
- MOET — FSH given to cow → superovulation (6–8 eggs) → blastocysts (8–32 cell stage) transferred to surrogate mothers.
Key Points: Genetic Engineering
Key Points: DNA Fingerprinting
- DNA fingerprinting is a technique used to identify individuals based on unique patterns in their DNA, mainly using VNTRs (Variable Number Tandem Repeats), also called minisatellites.
- VNTRs are short repetitive DNA sequences that show high variation among individuals, making each DNA profile unique (except identical twins).
- The technique was developed by Alec Jeffreys and even a very small amount of DNA can be used for analysis.
- The process involves DNA extraction from samples like blood, hair, semen, or tissue, followed by PCR amplification if needed and restriction enzyme digestion.
- DNA fragments are separated using gel electrophoresis, transferred to a membrane by Southern blotting, and hybridised with specific VNTR probes.
- The hybridised DNA is visualized using autoradiography, producing a unique banding pattern for each individual.
- DNA fingerprinting is widely used in forensic science, paternity testing, criminal investigations, identification, genetic diversity studies, and disease diagnosis.
