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CBSE Class 12 Biology Biotechnology And Its Application Revision Notes

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CBSE Class 12 Chapter 10 Biotechnology and Its Applications: Biotechnology refers to the production of biopharmaceuticals and biologicals on a large scale, which involves using genetically modified organisms such as microbes, fungi, plants, and animals. Biotechnology has various applications, including producing therapeutics, diagnostics, genetically modified crops, processed food, bioremediation, waste treatment, and energy production. Biotechnology has three key research areas: improving the catalyst as an organism or enzyme, engineering the ideal conditions for the catalyst to act, and developing downstream processing technologies for purifying proteins or organic compounds. In this article, we will discuss the CBSE Class 12 Chapter 10 Biotechnology and Its Applications. 

Biotechnology Applications

Scientists used biotechnology in a wide range of modifications and production of various products which are useful to humans. The following are the different applications of biotechnology are:

Biotechnological Applications in Agriculture

The term “Green Biotechnology” or “Green Revolution” refers to the use of biotechnology in agriculture. Agriculture has greatly benefited from biotechnology, including Organic agriculture, Agrochemical based agriculture, and Genetically engineered crop-based agriculture.

Agriculture Application

 

Despite successfully tripling the food supply, the Green Revolution was unable to keep up with the demands of the growing human population. While the use of improved crop varieties contributed to increased yields, the majority of the success can be attributed to better management practices and the use of agrochemicals such as fertilizers and pesticides. However, farmers in the developing world often cannot afford these agrochemicals, and conventional breeding methods are insufficient for further yield increases with existing crop varieties.

Tissue culture technology was developed to overcome this challenge during the 1950s. Scientists discovered that whole plants could be generated from explants. This process, called totipotency, involves providing the explants with carbon sources like sucrose, inorganic salts, vitamins, amino acids, and growth regulators like auxins and cytokinins. This technique, called micro-propagation, can propagate a large number of plants in a short duration, and each plant will be genetically identical to the original plant. Many essential food crops, such as tomatoes, bananas, and apples, have been commercially produced using this technique. 

Another important use of this method is to recover healthy plants from infected ones. Even if a plant is infected with a virus, the meristem (the growing tip of the plant) is usually free from the virus. Therefore, researchers can remove the meristem and grow it in a lab to obtain virus-free plants. Scientists have successfully cultured meristems from various plants, including bananas, sugarcane, and potato.

Furthermore, researchers have isolated individual cells from plants and removed their cell walls to obtain naked protoplasts, which are surrounded by plasma membranes. By fusing protoplasts from two different plant varieties with desirable traits, researchers can create hybrid protoplasts that can be grown to form a new plant, called somatic hybridization. The resulting hybrids are called somatic hybrids. For instance, researchers have fused a protoplast from a tomato with one from a potato to create a pomato plant, which combines the characteristics of both plants. Unfortunately, the pomato did not have all the desired traits for commercial use.

Genetically Modified Organisms (GMOs) are organisms that have had their genes manipulated by humans, including plants, bacteria, fungi, and animals. GMO plants offer several benefits, such as increased tolerance to environmental stressors like drought, heat, and salt, reduced reliance on chemical pesticides through the creation of pest-resistant crops, and improved efficiency of mineral usage by plants, which prevents soil fertility depletion. GM has also been used to create custom plants that provide alternative resources like starches, fuels, and pharmaceuticals for various industries.

A significant example of biotechnology in agriculture is the production of pest-resistant plants that could potentially decrease the use of chemical pesticides. This is done by cloning the Bt toxin gene from Bacillus thuringiensis bacteria and expressing it in plants, creating a bio-pesticide that provides insect resistance. Some crops that have been genetically modified using the Bt toxin gene include cotton, corn, rice, tomato, potato, and soybean.

Scientists have developed a method to protect tobacco plants from infestation by a harmful nematode called Meloidegyne incognita. This method is based on RNA interference (RNAi), a natural defense mechanism found in all eukaryotic organisms. RNAi involves silencing specific mRNA molecules by complementary dsRNA molecules, which prevent mRNA translation. The dsRNA can be generated from sources such as viral infections or mobile genetic elements. Researchers introduced nematode-specific genes into tobacco plants using Agrobacterium vectors in this case. The introduced DNA produced sense and anti-sense RNA in the plant cells, which formed a complementary dsRNA that initiated RNAi and silenced the specific mRNA of the nematode. As a result, the nematode could not survive in transgenic plants expressing the interfering RNA, and the plants were protected from infestation.

Biotechnological Applications in Medicine

Recombinant DNA technology has significantly impacted healthcare by allowing for the mass production of safe and more efficient therapeutic drugs. Unlike similar products obtained from non-human sources, recombinant therapeutics do not typically cause undesired immune responses. Approximately 30 approved recombinant therapeutics are currently for human use worldwide, with 12 available in India.

Genetically Engineered Insulin

Genetically Engineered Insulin

 

The management of adult-onset diabetes involves regular insulin intake, but if they don’t have access to enough human insulin, One option is to isolate insulin from other animals, but this raises questions about its effectiveness and potential immune response in humans. However, the discovery of bacteria capable of producing human insulin simplifies the process of insulin production. Oral administration of insulin to diabetic patients is impossible due to its breakdown in the digestive system. Previously, insulin was obtained from animal sources, but it caused allergic reactions in some patients due to foreign proteins. Insulin consists of two polypeptide chains linked together by disulfide bridges, and the C peptide, present in pro-hormone, is removed during maturation into insulin. In 1983, Eli Lilly successfully produced human insulin using recombinant DNA technology by introducing DNA sequences corresponding to A and B chains of human insulin in E. coli plasmids. The separate chains were extracted and combined to form mature human insulin by creating disulfide bonds.

Also Read: Genetically engineered insulin

Gene Therapy

Gene Therapy

 

Gene therapy is a technique used to correct genetic defects that a person is born with, which involves inserting normal genes into their cells and tissues. This method aims to compensate for non-functional genes and take over their function. A 4-year-old girl with ADA deficiency, a condition brought on by deleting the adenosine deaminase gene essential for the immune system’s operation, received the first clinical use of gene therapy in 1990. Treatments for this deficit include enzyme replacement therapy and bone marrow transplantation; however, they are not completely curative. Before being given back to the patient, lymphocytes from the patient’s blood are cultured, exposed to a functional ADA cDNA using a retroviral vector, and then grown in culture. The patient needs regular infusions of genetically modified lymphocytes because these cells are not immortal. A lasting treatment could be achieved by early injection of the gene isolated from marrow cells expressing ADA into cells during embryonic stages.

Molecular Diagnosis

Molecular Diagnosis

 

Early diagnosis and understanding of the pathophysiology of the disease are crucial for effective treatment. However, conventional diagnostic methods are not always able to detect diseases at an early stage. Recombinant DNA technology, Polymerase Chain Reaction (PCR), and Enzyme-Linked Immuno-sorbent Assay (ELISA) are some techniques that can be used for early detection.

PCR is particularly useful in detecting low concentrations of pathogens, such as bacteria and viruses, before the symptoms of the disease become visible. This is done by amplifying the nucleic acid of the pathogen through PCR. The method is now frequently used to identify gene mutations in patients suspected of having cancer or other genetic illnesses and HIV in patients suspected of having AIDS.

ELISA, on the other hand, detects the presence of antigens or antibodies synthesized against the pathogen to identify an infection. Using a radioactive molecule (probe) tagged to a single-stranded DNA or RNA makes it possible to detect gene mutations by allowing the probe to hybridize with its complementary DNA in a clone of cells.

Also Read: Molecular Diagnosis

Transgenic Animals

Transgenic animals refer to animals that have been genetically modified to carry and exhibit an additional foreign gene. While various animals, including rats, rabbits, pigs, sheep, cows, and fish, have been genetically modified to be transgenic, it is worth noting that the vast majority (over 95%) of transgenic animals in existence are mice. Common reasons for the development of transgenic animals are:

Transgenic Animal

 

  • In order to examine how genes are controlled and how they impact a person’s development and daily functions, transgenic animals can be particularly developed, for example, in the study of intricate growth-related factors like insulin-like growth factors. Information regarding the biological function of the factor in the body is discovered by introducing genes from different species that modify the creation of the factor and by examining the biological repercussions that follow. 
  • Transgenic animals are commonly used to enhance our comprehension of how genes influence the onset and progression of diseases. They are specifically engineered to serve as models for human diseases, enabling researchers to investigate and develop new treatments. Transgenic animal models are available for numerous human diseases, including but not limited to cancer, cystic fibrosis, rheumatoid arthritis, and Alzheimer’s.
  • Researchers are creating transgenic mice to evaluate the safety of vaccines before conducting human trials. Specifically, they are testing the reliability of these mice to assess the safety of the polio vaccine. If the results are promising, transgenic mice may replace the use of monkeys in evaluating vaccine safety.
  • Toxicology/safety testing of chemicals is applied to testing medication toxicity. Genes are inserted into transgenic animals to increase their sensitivity to toxins compared to non-transgenic animals. After which, the impacts of the harmful compounds are evaluated. We can get data faster by testing for toxicity in these animals.
  • Biological products used in medicines for treating certain diseases can be expensive to produce. One solution is to create transgenic animals by introducing a specific portion of DNA or genes that code for useful biological products, such as human proteins like α-1-antitrypsin, used to treat emphysema. Researchers are also attempting to use transgenic animals to treat conditions like phenylketonuria (PKU) and cystic fibrosis. The first transgenic cow, named Rosie, produced milk fortified with human protein in 1997. The milk contained human alpha-lactalbumin and was a more nutritionally balanced product for human babies than natural cow milk.

Ethical Issues

The manipulation of living organisms by humans requires ethical standards and regulations to evaluate the impact on the organisms and the ecosystem. The Indian Government has established the GEAC, which evaluates GM research and decides if it is safe to introduce GM organisms for public use. Meanwhile, a patent is a government-granted right to an inventor to prevent others from using their invention commercially. This also applies to biological resources and their derived products. Biopiracy is the unauthorized use of these resources by organizations without proper compensation or authorization from the concerned countries and people. In 1997, an American company obtained patent rights on Basmati rice, claiming it as a new variety, which had actually been derived from Indian farmers’ varieties. There have also been efforts to patent products and processes based on traditional Indian herbal medicines like turmeric and neem. 

Also Read: Ethical Issues

FAQs on Biotechnology and Its Applications

Q1: Biopiracy should be avoided. Describe how and why. 

Answer: 

Biopiracy needs to be stopped because the involved nations and people do not receive a sufficient amount of compensation. Additionally, the nations/people lose the ability to cultivate and conduct breeding studies to enhance other types of the same species. The introduction of particular rules that address all issues linked to biopatents and biopiracy may be used to prevent it.

Q2: Mention any two advantages that came from transgenic animals 

Answer:  

  • They are used as models for researching human ailments.
  • They generate valuable biological products by introducing a fragment of a gene that codes for a specific product, such as human protein a-1-antitrypsin, which is used to treat emphysema.

Q3: Identify the insect that consumes cotton bolls. Describe how Bacillus thuringiensis works to protect the cotton crop from pests and enhance productivity.

Answer: 

The Bt toxin protein exists as an inactive protoxin in bacteria, but once an insect consumes this toxin, it becomes activated due to the alkaline pH of the gut, which dissolves the crystals. The activated toxin attaches to the surface of midgut epithelial cells, creating pores that cause cell swelling and lysis, resulting in the insect’s death. Several crop plants have been modified to incorporate specific Bt toxin genes that are insect-group specific, with the toxin being encoded by a gene named cry.



Last Updated : 11 May, 2023
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