Revision: Applications of Biotechnology Zoology HSC Science Class 12 Tamil Nadu Board of Secondary Education

The technique of treating genetic disorders by correcting defective genes in somatic cells is called gene therapy.

A transgenic animal is an animal whose genome has been artificially modified to contain one or more genes from another species.

Gene cloning is a genetic engineering technique in which a single copy of a gene or DNA segment is isolated and multiplied to produce many identical copies.

The production of a complete organism by fusion of a somatic cell nucleus with an enucleated ovum is called reproductive cloning.

The technique of producing stem cells from cloned embryos for treatment of diseases is called therapeutic cloning.

The process of producing an exact genetic replica of a cell, tissue, organ, or entire organism is called cloning.

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Cloning is the process of producing identical copies of a gene, DNA fragment, cell, or organism.

Bioethics are a set of standards that may be used to regulate our activities in relation to the biological world.

Bioethics is the branch of ethics that deals with moral principles and issues arising from advances in biology, medicine, and life sciences.

• Gene therapy is the treatment of diseases by replacing, altering, or adding genes to correct genetic defects.
• It is used to treat genetic disorders such as haemophilia, cystic fibrosis, sickle cell anaemia, and thalassaemia.
• Genes can be delivered into cells by ex vivo (outside the body), in vivo (inside the body), or using vectors like viruses and liposomes.
• There are two types: germ-line therapy (affects future generations, not used in humans) and somatic cell therapy (affects only the patient and is commonly used).
• Gene therapy has applications in treating genetic diseases, cancer, and improving immune response, but it involves technical and ethical challenges.

• Stem cell therapy utilises stem cells as a medical intervention to prevent and manage various diseases.
• Bone-marrow transplantation is currently the most universally accepted and widely practised form of this therapy.
• It is routinely and successfully employed to treat congenital immunodeficiency disorders, such as SCID.
• The therapy is a standard treatment for severe blood-related conditions, including leukaemia, sickle cell anaemia, and thalassaemia.
• It offers significant therapeutic potential for repairing physical trauma, such as brain and spinal cord injuries, as well as general wound healing.
• Emerging applications target a diverse range of conditions, including diabetes, osteoarthritis, Parkinson’s disease, and the restoration of vision and hearing.

• Conventional serum and urine analyses are ineffective for early disease detection, making modern molecular methods essential for effective medical treatment.
• Advanced techniques like Polymerase Chain Reaction (PCR), ELISA, and recombinant DNA technology allow for the diagnosis of diseases even before visible symptoms appear.
• PCR facilitates early detection by amplifying the nucleic acids of pathogens, enabling the identification of extremely low concentrations of viruses like HIV.
• PCR is additionally utilised as a highly effective tool to detect specific gene mutations in suspected cancer patients and to diagnose various genetic disorders.
• During autoradiography, a radioactive probe hybridises to complementary DNA; mutations are identified because the probe fails to bind to the mutated sequence, leaving it unobserved on the photographic film.

• Transgenic animals have artificially modified genomes containing specific foreign genes from other species.
• They are produced by isolating a desired gene, inserting it into a host embryo, and growing it into a complete animal expressing the new trait.
• They serve as essential living models for studying normal physiology, understanding complex diseases, and testing the safety of vaccines and chemicals.
• They function as biological factories for therapeutic products, such as "Rosie", the first transgenic cow that produced human protein-enriched milk.
• Mice are the most widely used models in disease research, while other animals such as sheep, pigs, and fish are utilised for medical and agricultural advancements.

• Cloning is the process of producing an exact genetic copy of a gene, cell, tissue, or organism.
• Gene cloning isolates and multiplies a single DNA segment to produce medically useful proteins.
• Reproductive cloning fuses a somatic cell nucleus with an enucleated egg to produce a complete organism.
• Therapeutic cloning derives stem cells from cloned embryos for disease treatment and medical research.
• Dolly the sheep was the first mammal cloned from an adult somatic cell using somatic cell nuclear transfer (SCNT).
• Cloning is associated with low technical efficiency, health abnormalities in offspring, and significant ethical concerns.

• Bioethics sets moral standards to safely regulate biotechnology and prevent the misuse of biological resources.
• Major ethical concerns focus on preventing animal suffering in research and avoiding the ecological risks of cross-species gene transfer.
• Biosafety protocols are essential to protect human health and the environment from the unpredictable effects of genetically modified organisms (GMOs).
• The Genetic Engineering Appraisal Committee (GEAC) strictly evaluates and regulates the safe release of genetically engineered products into the environment.