- Transgenic animals are those whose genome is altered by introducing genes from another species.
- They are produced by methods such as DNA microinjection, retrovirus-mediated transfer, and embryonic stem cell transfer.
- Transgenic animals help in studying gene function, regulation, and normal growth and development.
- They are used as disease models to understand disorders like cancer and Alzheimer’s and to develop medicines and vaccines.
- Transgenic animals produce biological products (e.g., human proteins in milk) and are used for vaccine and chemical safety testing.
Definitions [8]
Definition: Bt Toxin
The soil bacterium, Bacillus thuringiensis (Bt) produces an insecticidal protein called Bt toxin.
Definition: Stem cells
Stem cells are undifferentiated; unspecialised, totipotent cells that can divide indefinitely for self‑renewal and have the potential to differentiate into different types of specialised cells.
Definition: Gene Therapy
The technique of treating genetic disorders by correcting defective genes in somatic cells is called gene therapy.
Definition: ELISA (Enzyme-Linked Immunosorbent Assay)
ELISA is an immunological test based on the antigen–antibody reaction, used to detect and measure antigens or antibodies in biological samples.
Definition: Transgenic Animal
A transgenic animal is an animal whose genome has been artificially modified to contain one or more genes from another species.
Definition: Biopiracy
Biopiracy is defined as ‘theft of various natural products and then selling them by getting patent without giving any benefits or compensation back to the host country’.
or
It is an unauthorised misappropriation of any biological resource and indigenous knowledge.
Definition: Biopatent
Patents granted for biological entities and for products derived from them are called biopatents.
Definition: Bioethics
Bioethics are a set of standards that may be used to regulate our activities in relation to the biological world.
Key Points
Key Points: Applications of Biotechnology in Agriculture
- Biotechnology helps in increasing crop yield and food production.
- It promotes the use of biofertilizers and biopesticides instead of harmful chemicals.
- Genetically modified crops improve resistance to pests and diseases.
- It allows precise introduction of useful genes to improve crop quality.
Key Points: Features of Genetically Modified Crops
- GM crops are developed to tolerate abiotic stresses such as drought, salinity, heat, and cold.
- They show pest resistance, reducing the use of chemical pesticides (e.g., Bt cotton).
- GM crops help in reducing post-harvest losses by increasing shelf life of fruits and vegetables.
- They improve nutritional value of food, such as vitamin A–rich Golden Rice.
- GM plants are also used for industrial purposes and environmental cleanup (phytoremediation).
Key Points: Pest-Resistant Plants
- Nematode pests like Meloidogyne incognita damage plant roots, reduce crop yield, and require bioengineering for resistance.
- RNA interference (RNAi) is used to silence pest genes by preventing translation of nematode mRNA.
- In transgenic tobacco, both sense and antisense RNA are produced, forming dsRNA that triggers post-transcriptional gene silencing.
- Agrobacterium tumefaciens is used as a vector to transfer nematode-specific genes, making plants pest resistant.
Key Points: Genetically Engineered Insulin
- Earlier insulin was obtained from animals, which caused allergic reactions and could not meet large-scale demand.
- Recombinant DNA technology enabled large-scale production of human insulin, first produced in 1983 as Humulin®.
- Human insulin consists of two polypeptide chains (A and B) that are produced separately in E. coli using plasmid vectors.
- The purified A and B chains are joined by disulphide bonds to form active human insulin.
Key Points: Vaccine Production
- Vaccines produced using recombinant DNA technology are called recombinant or subunit vaccines, such as the hepatitis-B vaccine.
- These vaccines may be protein vaccines (using specific antigens) or DNA vaccines that induce an immune response.
- Examples include hepatitis-B vaccine produced in yeast, rotavirus, dengue, HPV vaccines, and plant-based edible vaccines.
Key Points: Gene Therapy
- Gene therapy is a technique used to treat genetic disorders by replacing a defective gene with a functional gene.
- Viral vectors are commonly used to deliver the therapeutic gene into the patient’s target cells.
- It is especially effective for single-gene disorders such as sickle cell anaemia, cystic fibrosis, and SCID.
- In ADA deficiency, functional ADA gene is introduced into patient’s lymphocytes, improving immune function, though repeated treatment may be required.
Key Points: Molecular Diagnosis
- Molecular diagnosis enables early detection of diseases using techniques like PCR and ELISA before symptoms appear.
- PCR detects very low levels of pathogen DNA or RNA by amplification and is used for diseases like HIV and genetic disorders.
- DNA probes labeled with radioactive markers help identify mutations by hybridization and autoradiography.
Key Points: Transgenic Animal
Important Questions [11]
- In the Following Questions/Statements Has Four Suggested Answers. Rewrite the Correct Answer Bt Cotton is Resistant to
- Explain the term biofortification.
- Give a reason for the following: Streptokinase is administered to the patients having myocardial infarction.
- The diagram given below represents the schematic structure of proinsulin, which undergoes certain modifications before it becomes a fully functional insulin.
- State the Best-known Contribution Of P.K. Sethi
- Explain how insulin can be produced using recombinant DNA technology.
- In humans, somatic gene therapy was carried out to correct an immunodeficiency disease. Name this disease.
- Explain the role of stem cells in medical treatment.
- Give Four Points of Anatomical Differences Between a Monocot Stem and a Dicot Stem
- Scientific Term for the Hydrostatic Pressure Developed Inside the Cell on the Cell Wall Due To Endosmosis.
- What is cryopreservation?
Concepts [19]
- Core Objectives of Biotechnological Research
- Applications of Biotechnology in Agriculture
- Features of Genetically Modified Crops
- Bt Cotton
- Pest-Resistant Plant
- Mechanism of RNA Interference
- Applications of Biotechnology in Health and Medicine
- Genetically Engineered Insulin
- Vaccine Production
- Stem Cell Technology
- Stem Cell Therapy
- Gene Therapy
- Molecular Diagnosis
- ELISA
- Transgenic Animals
- Role of GEAC in Regulating Genetically Modified Organisms in India
- Biopiracy
- Biopatent
- Bioethical Issues
