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Biotechnology and its Applications - Transgenic Animals

Grade 12CBSEBiology

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

Transgenic animals are those that have had their DNADNA manipulated to possess and express an extra (foreign) gene. Common examples include transgenic rats, rabbits, pigs, sheep, cows, and fish.

Over 95%95\% of all existing transgenic animals are mice, primarily due to their short life cycle and ease of genetic manipulation.

Transgenic animals are used to study how genes are regulated and how they affect the normal functions of the body and its development (e.g., studying the role of insulin-like growth factor).

Many transgenic animals are designed to increase our understanding of how genes contribute to the development of disease. Transgenic models exist for many human diseases such as cancer, cystic fibrosis, rheumatoid arthritis, and Alzheimer’s.

Transgenic animals are used to produce biological products. For example, the human protein α1antitrypsin\alpha-1-antitrypsin is produced to treat emphysema. Similar attempts are being made for treatment of phenylketonuria (PKUPKU) and cystic fibrosis.

In 19971997, the first transgenic cow, Rosie, produced human protein-enriched milk (2.42.4 grams per litre). The milk contained the human α\alpha-lactalbumin and was nutritionally more balanced for human babies than natural cow milk.

Transgenic mice are being developed for use in testing the safety of vaccines before they are used on humans, such as the polio vaccine. If successful and found to be reliable, they could replace the use of monkeys to test the safety of batches of the vaccine.

Chemical safety testing (Toxicity testing): Transgenic animals are made that carry genes which make them more sensitive to toxic substances than non-transgenic animals. They are then exposed to the toxic substances and the effects studied.

Ethical Issues and GEACGEAC: The Indian Government has set up organizations such as GEACGEAC (Genetic Engineering Appraisal Committee), which will make decisions regarding the validity of GMGM (Genetically Modified) research and the safety of introducing GMGM-organisms for public services.

📐Formulae

Protein concentration in Rosie’s milk=2.4 g/L\text{Protein concentration in Rosie's milk} = 2.4 \text{ g/L}

Percentage of Transgenic Mice>95%\text{Percentage of Transgenic Mice} > 95\%

α1antitrypsinTreatment for Emphysema\alpha-1-antitrypsin \rightarrow \text{Treatment for Emphysema}

💡Examples

Problem 1:

Calculate the total amount of human α\alpha-lactalbumin protein produced by the transgenic cow 'Rosie' if she yields 1515 litres of milk in a day.

Solution:

Given the protein concentration is 2.4 g/L2.4 \text{ g/L}: Total Protein=Concentration×Volume\text{Total Protein} = \text{Concentration} \times \text{Volume} Total Protein=2.4 g/L×15 L=36 g\text{Total Protein} = 2.4 \text{ g/L} \times 15 \text{ L} = 36 \text{ g}

Explanation:

Rosie's milk is enriched with the human protein α\alpha-lactalbumin at a specific concentration of 2.4 g/L2.4 \text{ g/L}. By multiplying the daily volume of milk by this concentration, we find the total daily yield of the therapeutic protein.

Problem 2:

A researcher is studying the effects of a new drug on AlzheimersAlzheimer's disease using a transgenic mouse model. Why is the mouse considered 'transgenic' in this context?

Solution:

The mouse is 'transgenic' because its genome has been intentionally altered by the insertion of human genes associated with AlzheimersAlzheimer's disease.

Explanation:

Transgenic animals serve as biological models. By inserting specific human disease-linked genes into the mouse genome, researchers can observe the progression of the disease and test potential treatments in a living system that mimics human pathology.

Transgenic Animals - Revision Notes & Key Diagrams | CBSE Class 12 Biology