Biotechnology is the application of biological techniques to solve problems and create products for human benefit. It involves using living organisms or their components to develop products and processes.
Principles of Biotechnology
- Genetic Engineering: Modifying the genetic material of organisms to introduce new traits or improve existing ones.
- Recombinant DNA Technology: Joining DNA fragments from different sources to create new DNA molecules.
- Cloning: Producing identical copies of an organism or DNA sequence.
Tools of Biotechnology
- Restriction Enzymes: Cut DNA at specific sequences, creating fragments.
- Cloning Vectors: Plasmids or viruses used to carry foreign DNA into a host cell.
- Gel Electrophoresis: Separates DNA fragments based on size.
- Polymerase Chain Reaction (PCR): Amplifies DNA fragments.
Applications of Biotechnology
- Agriculture: Developing genetically modified crops with improved traits, such as pest resistance and higher yields.
- Medicine: Producing vaccines, antibiotics, and therapeutic proteins.
- Environmental Biotechnology: Bioremediation of pollution and waste management.
- Industrial Biotechnology: Production of enzymes, chemicals, and biofuels.
Key Techniques:
- Genetic Engineering: Altering the genetic makeup of organisms.
- Hybridization: Crossing different species to create hybrids with desirable traits.
- Tissue Culture: Growing cells or tissues in a controlled environment.
Exercise
1. Which part of the plant is best suited for making virus-free plants and why?
Ans :
The apical meristem is the best part of a plant for making virus-free plants.
Here’s why:
- Meristematic Cells: Apical meristems are regions of actively dividing cells located at the tips of stems and roots. These cells are undifferentiated and have not yet been infected by viruses.
- Virus-Free Growth: By culturing apical meristems, it is possible to regenerate virus-free plants. This is because viruses cannot infect cells that are actively dividing.
- Micropropagation: Apical meristem culture can also be used for micropropagation, which is the production of large numbers of genetically identical plants from a single plant.
2. What is the major advantage of producing plants by micropropagation?
Ans :
The major advantage of producing plants by micropropagation is the rapid production of a large number of genetically identical plants.
Here are some other key benefits of micropropagation:
- Disease-free plants: Micropropagation can produce plants that are free from viruses and other pathogens, ensuring healthy and productive crops.
- Preservation of rare or endangered species: Micropropagation can be used to propagate rare or endangered plant species, helping to conserve biodiversity.
- Production of elite clones: Plants with desirable traits can be propagated to produce large numbers of genetically identical individuals.
- Year-round production: Micropropagation allows for the production of plants throughout the year, regardless of the growing season.
- Reduced time to market: Micropropagated plants can be produced in a shorter time span compared to traditional propagation methods.
3. Find out what the various components of the medium used for propagation of an explant in vitro are?
Ans :
The in vitro propagation of explants requires a carefully prepared culture medium that provides all the necessary nutrients and conditions for optimal growth. The medium typically consists of the following components:
1. Carbon Source: Provides energy for the explants. Sucrose is commonly used as a carbon source.
2. Inorganic Salts: Supplies essential minerals and nutrients, such as nitrogen, phosphorus, potassium, calcium, magnesium, and trace elements.
3. Vitamins: Provides vitamins and co-factors necessary for plant growth and development.
4. Amino Acids: Supplies amino acids, the building blocks of proteins.
4. Crystals of Bt toxin produced by some bacteria do not kill the bacteria themselves because –
(a) bacteria are resistant to the toxin
(b) toxin is immature;
(c) toxin is inactive;
(d) bacteria encloses toxin in a special sac.
Ans :
c) toxin is inactive is the correct statement.
Toxins produced by bacteria are often inactive when inside the bacterial cell. They are activated only when released into the environment or taken up by a host organism. This mechanism helps protect the bacteria from self-intoxication.
5. What are transgenic bacteria? Illustrate using any one example.
Ans :
This process involves inserting a foreign gene into the bacterial chromosome or a plasmid, allowing the bacteria to produce the protein encoded by the gene.
Example:
One well-known example of transgenic bacteria is the production of human insulin using Escherichia coli (E. coli). The human insulin gene is inserted into a plasmid, which is then introduced into E. coli cells. These transformed E. coli cells can then produce human insulin in large quantities. This recombinant insulin is used to treat patients with diabetes.
6. Compare and contrast the advantages and disadvantages of production of genetically modified crops
Ans :
| Feature | Advantages | Disadvantages |
| Yield | Increased yield | Potential environmental impacts |
| Pest Resistance | Reduced need for chemical pesticides | Concerns about the spread of genetically modified genes |
| Herbicide Resistance | More efficient weed control | Potential economic issues for small farmers |
| Nutritional Value | Enhanced nutritional content | Health concerns (unsubstantiated) |
| Environmental Tolerance | Tolerance to drought, salinity, or extreme temperatures | Regulatory challenges and trade barriers |
| Economic Benefits | Increased profits for farmers | Potential dominance of large corporations |
7. What are Cry proteins? Name an organism that produce it. How has man exploited this protein to his benefit?
Ans :
Cry proteins are insecticidal proteins produced by certain species of bacteria, particularly those belonging to the genus Bacillus. They are toxic to insects and are used as biological insecticides.
One example of a bacterium that produces Cry proteins is Bacillus thuringiensis (Bt). Bt produces a variety of Cry proteins that are toxic to different groups of insects, including caterpillars, beetles, and flies.
Humans have exploited Cry proteins in several ways:
- Transgenic Crops: Bt genes have been introduced into plants, creating Bt crops that are resistant to insect pests. These crops reduce the need for chemical insecticides, which can harm beneficial insects and the environment.
- Biological Pesticides: Cry proteins can be formulated into biological insecticides and applied directly to crops to control insect pests.
- Biocontrol Agents: Bt can be used as a biological control agent in integrated pest management programs, where it is applied in combination with other pest control methods.
8. What is gene therapy? Illustrate using the example of adenosine deaminase (ADA) deficiency.
Ans :
Gene therapy is a technique that involves introducing a functional gene into a patient’s cells to correct a genetic defect or treat a disease. This is done by delivering a therapeutic gene into the target cells, where it is integrated into the host genome and produces the desired protein.
Example: Adenosine Deaminase (ADA) Deficiency
Adenosine deaminase (ADA) deficiency is a rare genetic disorder that results in a severe combined immunodeficiency (SCID). Patients with ADA deficiency lack the enzyme ADA, which is essential for the proper functioning of the immune system. As a result, they are highly susceptible to infections and have a very low life expectancy.
9. Digrammatically represent the experimental steps in cloning and expressing an human gene (say the gene for growth hormone) into a bacterium like E. coli ?
Ans :
Steps:
- Isolation of the human growth hormone gene: The gene is isolated from human DNA using restriction enzymes.
- Vector Preparation: A plasmid vector is prepared by cutting it with the same restriction enzyme used to isolate the gene. This creates compatible sticky ends on both the gene and the vector.
- Ligation: The human growth hormone gene is inserted into the plasmid vector using DNA ligase, creating a recombinant DNA molecule.
- Transformation: The recombinant DNA molecule is introduced into E. coli cells using a transformation method, such as electroporation or chemical transformation.
- Selection: Cells that have successfully taken up the recombinant DNA are selected using an antibiotic resistance marker on the plasmid.
- Growth and Expression: The transformed E. coli cells are grown in a culture medium under conditions that promote the expression of the human growth hormone gene.
- Protein Purification: The human growth hormone protein is purified from the bacterial culture using techniques such as chromatography and filtration.
10. Can you suggest a method to remove oil (hydrocarbon) from seeds based on your understanding of rDNA technology and chemistry of oil?
Ans :
Identification of a suitable enzyme: Research and identify an enzyme capable of breaking down the protein and carbohydrate matrix surrounding the oil. This enzyme could potentially be isolated from microorganisms that naturally degrade plant material.
Genetic engineering: Introduce the gene encoding this enzyme into a suitable host organism, such as E. coli or yeast. This would create a transgenic organism that produces the desired enzyme.
Optimization: Optimize the expression of the enzyme in the host organism to ensure high levels of production.
Application: Treat the oil-containing seeds with the purified enzyme. The enzyme would degrade the matrix, releasing the oil.
Separation: The released oil can then be separated from the plant material using traditional methods such as pressing or solvent extraction.
11. Find out from internet what is golden rice.
Ans : Golden rice is a genetically modified variety of rice that has been engineered to produce beta-carotene, a precursor of vitamin A. It is intended to help address vitamin A deficiency, which is a major public health problem in many developing countries, particularly in South and Southeast Asia.
12. Does our blood have proteases and nucleases?
Ans :
Yes
- Proteases: They play a crucial role in digestion, immune function, and blood clotting. Some examples of proteases found in blood include trypsin, chymotrypsin, and plasmin.
- Nucleases:They are involved in various cellular processes, such as DNA repair, replication, and transcription. Nucleases are also found in the immune system, where they help degrade foreign nucleic acids.
13. Consult internet and find out how to make orally active protein pharmaceutical. What is the major problem to be encountered?
Ans :
Challenges in Creating Orally Active Protein Pharmaceuticals
Oral delivery of protein pharmaceuticals presents significant challenges due to the harsh conditions of the gastrointestinal (GI) tract. These conditions include:
- Low pH: The stomach’s acidic environment can degrade proteins.
- Enzymatic Degradation: Digestive enzymes can break down proteins before they reach the bloodstream.
- Absorption Barriers: The intestinal lining can be a barrier to the absorption of proteins.
