NCERT Solution Biotechnology and its Application class 12

Biotechnology and its Applications Class 12 Biology Chapter 12

In this chapter, all the Important Topics are covered by NCERT Book Biology Biotechnology and its Application class 12 Chapter 12 we covered like, Explanation Question and Answer or summary of the lesson and other important Points

Biotechnology and its Applications Class 12 Introduction

Biotechnology is like a magic toolkit of science that helps us use living organisms, cells, and molecules to create useful things. It’s like giving superpowers to living things to solve problems and make cool stuff. With biotechnology, we can do amazing things like making medicines, improving crops, and cleaning up pollution. It’s like nature’s own superhero helping us make the world a better place

Biotechnology and its Applications Class 12 Definition

Biotechnology is a branch of science where we use living things like cells, bacteria, and plants to make useful stuff or solve problems. It’s like using nature’s tools to create new medicines, improve agriculture, and do other cool things that help people and the environment.

Biotechnology and its Applications Class 12 Important Notes

1. What is Biotechnology?: Biotechnology is all about using living organisms or parts of them to make useful products or solve problems.
2. Applications of Biotechnology: It’s used in medicine to create vaccines, insulin, and other important medicines. In agriculture, it helps make crops resistant to pests and diseases, and it’s also used in making biofuels.
3. Genetic Engineering: This is a big part of biotechnology where scientists change the DNA of living things to make them do new things or produce useful substances.
4. Environmental Benefits: Biotechnology can help clean up pollution, like using bacteria to break down harmful chemicals in the environment.
5. Ethical Considerations: While biotechnology has many benefits, there are also ethical questions about things like genetically modified organisms (GMOs) and cloning that scientists and society need to think about.

Biotechnology and its Applications Class 12 Explanation

Biotechnology, as discussed in the previous chapter, primarily focuses on the industrial-scale production of biopharmaceuticals and biologicals utilizing genetically modified microbes, fungi, plants, and animals. Its applications span various fields including therapeutics, diagnostics, genetically modified crops for agriculture, processed food, bioremediation, waste treatment, and energy production. Three critical research areas within biotechnology include

(i) Providing the best catalyst in the form of improved
organism usually a microbe or pure enzyme.
(ii) Creating optimal conditions through engineering for
a catalyst to act, and
(iii) Downstream processing technologies to purify the
protein/organic compound.

Let us now delve into how humanity has leveraged biotechnology to enhance the quality of human life, particularly in the realms of food production and health.

10.1 BIOTECHNOLOGICAL APPLICATIONS IN AGRICULTURE

Let us take a look at the three options that can be thought of for increasing food production

(i) agrochemical based agriculture

(ii) organic agriculture; and
(iii) genetically engineered crop-based agriculture

The Green Revolution achieved a tripling of the food supply, yet it fell short of meeting the demands of the expanding human population.

While increased yields were partially attributed to the use of improved crop varieties, the primary drivers were better management practices and the utilization of agrochemicals (fertilizers and pesticides).

However, for farmers in developing countries, the cost of agrochemicals is often prohibitive, and further yield increases with existing varieties are unattainable through conventional breeding methods.

As traditional breeding techniques struggled to keep pace with demand and provide efficient systems for crop improvement, another technology called tissue culture emerged. Tissue culture involves the regeneration of whole plants from explants—any part of a plant taken out and grown in a sterile environment in specialized nutrient media.

This capacity to generate an entire plant from any cell/explant is known as totipotency. While the intricacies of this process will be explored in advanced classes, it’s crucial to note that the nutrient medium must contain a carbon source like sucrose, as well as inorganic salts, vitamins, amino acids, and growth regulators like auxins and cytokinins.

Through the application of tissue culture methods, it becomes possible to propagate a large number of plants in significantly short durations—a process termed micro-propagation. Each of these plants will be genetically identical to the original plant, thus referred to as

some clones. Many essential food plants, such as tomatoes, bananas, and apples, have been mass-produced using this method. Students are encouraged to visit tissue culture laboratories with their teachers to gain a deeper understanding of this process.

Another critical application of tissue culture is the recovery of healthy plants from diseased ones. Even if a plant is infected with a virus, the meristem (apical and axillary) remains free of the virus. Therefore, the meristem can be isolated and grown in vitro to obtain virus-free plants. Scientists have successfully cultured meristems of plants like banana, sugarcane, and potato

Furthermore, scientists have isolated single cells from plants and, after digesting their cell walls, obtained naked protoplasts (enclosed by plasma membranes).

Protoplasts from two different plant varieties—each possessing desirable traits—can be fused to create hybrid protoplasts, which can then be grown to form a new plant. These hybrids are known as somatic hybrids, and the process allows for the introduction of desirable traits into new plant varieties.

is called somatic hybridization. Imagine a scenario where a protoplast of tomato is fused with that of potato, and they are grown to form new hybrid plants combining characteristics of both tomato and potato.

This feat has indeed been accomplished, resulting in the formation of a “pomato”; unfortunately, this plant did not possess all the desired combinations of characteristics for commercial utilization.

Given the limitations of somatic hybridization, is there an alternative approach within our understanding of genetics that could help farmers achieve maximum yield from their fields

while minimizing the use of fertilizers and chemicals to reduce their harmful effects on the environment? Genetically modified crops offer a potential solution.

Plants, bacteria, fungi, and animals whose genes have been altered through manipulation are referred to as Genetically Modified Organisms (GMOs). GM plants have proven beneficial in various ways. Genetic modification has

(i) made crops more tolerant to abiotic stresses (cold, drought, salt, heat).
(ii) reduced reliance on chemical pesticides (pest-resistant crops).
(iii) helped to reduce post-harvest losses.
(iv) increased efficiency of mineral usage by plants (this prevents early
exhaustion of fertility of soil).
(v) enhanced nutritional value of food, e.g., golden rice, i.e., Vitamin ‘A’
enriched rice.

In addition to these applications, genetic modification (GM) has been utilized to develop customized plants capable of providing alternative resources to industries, such as starches, fuels, and pharmaceuticals.

Among the various applications of biotechnology in agriculture, one significant aspect you will explore in detail is the production of pest-resistant plants, which can potentially decrease the amount of pesticides used.

The Bt toxin, derived from a bacterium called Bacillus thuringiensis (Bt), plays a crucial role in this endeavor. The Bt toxin gene has been cloned from the bacterium and expressed in plants to confer resistance to insects, effectively creating a bio-pesticide. Examples include Bt cotton, Bt corn, rice, tomato, potato, and soybean, among others.

Bt Cotton: Certain strains of Bacillus thuringiensis produce proteins that are lethal to specific insects such as lepidopterans (e.g., tobacco budworm, armyworm), coleopterans (e.g., beetles), and dipterans (e.g., flies, mosquitoes).

During a particular phase of their growth, B. thuringiensis forms protein crystals containing a toxic insecticidal protein. Interestingly, this toxin does not harm the Bacillus itself. Initially, the Bt toxin protein exists as inactive protoxins, but once ingested by an insect, it is converted

into an active form of toxin due to the alkaline pH of the gut, which solubilizes the crystals. The activated toxin binds to the surface of midgut epithelial cells, creating pores that cause cell swelling, lysis, and eventual death of the insect.

Specific Bt toxin genes were isolated from Bacillus thuringiensis and incorporated into several crop plants, such as cotton (as illustrated in Figure 10.1). The selection of genes depends on the crop and the targeted pest, as most Bt toxins exhibit specificity towards

certain groups of insects. The toxin is encoded by a gene called acrylic, which is named cry. There are several variants of this gene. For instance, the proteins encoded by the genes cryIAc and cryIIAb target cotton bollworms, while that of cryIAb controls corn borers.

Pest Resistant Plants: Various nematodes parasitize a wide range of plants and animals, including human beings. One such nematode, Meloidogyne incognita, infects the roots of tobacco plants, leading to a significant reduction in yield. To combat this infestation, a novel strategy based on RNA interference (RNAi) was employed.

RNAi is a cellular defense mechanism found in all eukaryotic organisms, involving the silencing of specific mRNA molecules through the action of complementary double-stranded RNA (dsRNA) molecules, which bind to and inhibit mRNA translation.

The source of complementary RNA can stem from viral infections with RNA genomes or mobile genetic elements (transposons) that replicate via an RNA intermediate.

Using Agrobacterium vectors, nematode-specific genes were introduced into the host plant (as depicted in Figure 10.2). The introduced DNA was designed to produce both sense and anti-sense RNA strands within the host cells.

These complementary RNA strands formed a double-stranded RNA (dsRNA) that initiated RNAi, effectively silencing the specific mRNA of the nematode.

As a result, the parasite could not survive in a transgenic host expressing specific interfering RNA. Consequently, the transgenic plant became protected from the nematode parasite (as illustrated in Figure 10.2).

10.2 BIOTECHNOLOGICAL APPLICATIONS IN MEDICINE

Recombinant DNA technology has had a significant impact on healthcare by enabling the mass production of safe and more effective therapeutic drugs. Moreover, recombinant

therapeutics do not typically induce unwanted immunological responses, which are common with similar products isolated from non-human sources. Currently, approximately 30 recombinant therapeutics have been approved for human use worldwide, with 12 of these being marketed in India.

Genetically Engineered Insulin

The management of adult-onset diabetes relies on regular insulin intake. However, what if enough human insulin was not readily available? In such a scenario, the alternative would be to isolate and use insulin sourced from other animals.

However, insulin from other animals may not be as effective as that secreted by the human body and could potentially elicit an immune response in humans.

Now, consider the possibility of using bacteria to produce human insulin. Suddenly, the entire process becomes much simpler. It becomes feasible to grow a large quantity of bacteria and produce as much insulin as needed.

Regarding the oral administration of insulin to diabetic individuals, it poses challenges. Insulin used to be extracted from the pancreas of slaughtered cattle and pigs. However, insulin from animal sources often led to patients developing allergies or other adverse reactions due to the foreign protein content.

Insulin comprises two short polypeptide chains, chain A and chain B, which are linked together by disulfide bridges (as depicted in Figure 10.3).

In mammals, including humans, insulin is synthesized as a pro-hormone, akin to a pro-enzyme, which requires processing before it becomes a fully mature and functional hormone.

This pro-hormone includes an additional segment called the C peptide, which is absent in mature insulin and is removed during maturation.

The primary challenge in producing insulin using recombinant DNA (rDNA) techniques lay in assembling insulin into its mature form. In 1983, Eli Lilly, an American company, developed two DNA sequences corresponding to the A and B chains of human insulin and introduced

them into plasmids of Escherichia coli (E. coli) to produce insulin chains. The A and B chains were synthesized separately, extracted, and then combined by creating disulfide bonds, resulting in the formation of human insulin.

10.2.2 Gene Therapy

Can corrective therapy be pursued for a person born with a hereditary disease? Gene therapy aims to address this challenge. It encompasses a range of techniques designed to correct gene defects identified in children or embryos.

In gene therapy, genes are introduced into a person’s cells and tissues to treat a disease. Correcting a genetic defect entails delivering a normal gene into the individual or embryo to compensate for the non-functional gene.

The first clinical gene therapy was administered in 1990 to a 4-year-old girl diagnosed with adenosine deaminase (ADA) deficiency. ADA is a crucial enzyme for the immune system’s functioning.

The deficiency arises from the deletion of the gene responsible for adenosine deaminase production. While some children with ADA deficiency can be cured through bone marrow transplantation or enzyme replacement therapy, these approaches are not always fully curative.

In the initial stages of gene therapy, lymphocytes from the patient’s blood are cultured outside the body. Functional ADA cDNA is then introduced into these lymphocytes using a retroviral vector, after which they are returned to the patient.

However, since these cells are not immortal, the patient requires periodic infusions of genetically engineered lymphocytes. Yet, introducing the ADA-producing gene isolate from marrow cells into cells during early embryonic stages could potentially offer a permanent cure.

10.2.3 Molecular Diagnosis

For effective disease treatment, early diagnosis and understanding the disease’s pathophysiology are crucial. Conventional diagnostic methods such as serum and urine analysis are limited in their ability to detect diseases early.

Biotechnology and its Applications Class 12 Summary

Biotechnology has bestowed upon humanity numerous valuable products by leveraging microbes, plants, animals, and their metabolic machinery. Techniques like tissue culture and somatic hybridization offer immense potential for manipulating plants in vitro to generate

new varieties. Recombinant DNA technology has facilitated the engineering of microbes, plants, and animals, endowing them with novel capabilities. Genetically Modified Organisms (GMOs) have been developed by transferring one or more genes from one organism to another using techniques such as recombinant DNA technology, which goes beyond natural methods.

GM plants have proven instrumental in boosting crop yields, reducing post-harvest losses, and enhancing crop tolerance to stresses. Numerous GM crop plants exhibit improved nutritional value and reduced reliance on chemical pesticides, manifesting as pest-resistant crops. In the healthcare sector, recombinant DNA technology has had a profound impact by

enabling the mass production of safe and more effective therapeutics. Since recombinant therapeutics mirror human proteins, they do not trigger unwanted immunological responses or infection risks associated with products isolated from non-human sources. For instance, human insulin, synthesized in bacteria, possesses a structure identical to that of the natural molecule.

Transgenic animals serve as valuable models for understanding the genetic underpinnings of diseases such as cancer, cystic fibrosis, rheumatoid arthritis, and Alzheimer’s disease, thus contributing to disease research and drug development.

Gene therapy involves the insertion of genes into an individual’s cells and tissues to treat diseases, particularly hereditary ones. This therapy aims to replace defective mutant alleles with functional ones or utilizes gene targeting techniques involving gene amplification.

Viruses, which integrate their genetic material into host cells during their replication cycle, are harnessed as vectors to transfer healthy genes or portions of genes into target cells.

However, the current interest in manipulating microbes, plants, and animals has sparked serious ethical questions that warrant careful consideration and deliberation.

Biotechnology and its Applications Class 12 Question and Answer

Question:1 What are the applications of biotechnology class 12th?

Answer :

1. Healthcare Biotechnology: This includes the production of pharmaceuticals, vaccines, and diagnostic tools using biotechnological techniques. Students may learn about recombinant DNA technology, genetic engineering, and the production of biopharmaceuticals such as insulin and vaccines.
2. Agricultural Biotechnology: Students may study how biotechnology is used in crop improvement, including the development of genetically modified organisms (GMOs) with desirable traits such as pest resistance, drought tolerance, and improved nutritional content. They may also explore tissue culture, somatic hybridization, and marker-assisted selection techniques.
3. Environmental Biotechnology: This area focuses on the application of biotechnological processes to address environmental issues such as pollution remediation, waste management, and sustainable resource utilization. Topics may include bioremediation, biofuel production, and wastewater treatment using microbial processes.
4. Industrial Biotechnology: Students may learn about the use of microorganisms, enzymes, and biotechnological processes in various industries such as food and beverage, textile, and pharmaceutical manufacturing. This may involve studying fermentation processes, enzyme technology, and the production of bio-based materials.

Question:2 What are the principles and processes of biotechnology class 12?

Answer :The principles of biotechnology include the origin of DNA replication, the cloning process, plasmids, antibiotic resistance genes, vector technology, restriction enzyme method, and ligases. With the introduction of biotechnology, all living organisms can be genetically modified.

Question:3 What are the 5 applications of biotechnology?

Answer:

1. Healthcare biotechnology
2. Agricultural biotechnology
3. Environmental Biotechnology
4. Industrial biotechnology
5. Forensic biotechnology

Question:4 What is PCR in biotechnology class 12?

Answer: In biotechnology, studied in class 12, PCR (polymerase chain reaction) is a molecular biology technique used to amplify a specific segment of DNA (deoxyribonucleic acid). It is a common method for editing millions of copies of a specific DNA sequence.

Question:5 What is gene cloning class 12?

Answer: production of multiple copies of a particular gene by using techniques of genetic engineering.

Question:6 What are the 4 types of biotechnology?

Answer:

1. Medical biotechnology
2. Agricultural biotechnology
3. Industrial biotechnology
4. Environmental Biotechnology

Question:7 What is called plasmid?

Answer: A plasmid is a small circular DNA molecule found in bacteria and other viruses. It is independent of the bacterial chromosome and replicates spontaneously in the host cell. Plasmids often carry genes that give the bacteria various advantages, such as antibiotic

resistance, the ability to produce toxins, or the ability to metabolize certain nutrients. In biotechnology, plasmids are commonly used as vectors to transfer genes between different organisms during genetic engineering experiments.

Biotechnology and its Applications Class 12 Important MCQ

Question:1 Which of the following is NOT an application of biotechnology?

1. a) Healthcare
2. b) Agriculture
3. c) Industrial manufacturing
4. d) Astronomy

Question:2 PCR (Polymerase Chain Reaction) is used in biotechnology primarily for

1. a) DNA amplification
2. b) Protein synthesis
3. c) Cell imaging
4. d) Enzyme digestion

Question:3 What is the purpose of using plasmids in genetic engineering?

1. a) They are used to store genetic information.
2. b) They are used as energy sources for cells.
3. c) They act as vectors to transfer genes between organisms.
4. d) They regulate gene expression.

Question:4 Which of the following is an example of environmental biotechnology?

1. a) Production of antibiotics
2. b) Wastewater treatment
3. c) Crop improvement
4. d) Insulin production

Question:5 Genetic modification of crops is primarily aimed at

1. a) Increasing crop yield
2. b) Reducing pesticide use
3. c) Enhancing nutritional value
4. d) All of the above

Question:6 What is the function of DNA ligase in genetic engineering?

1. a) It amplifies DNA sequences.
2. b) It cuts DNA at specific sites.
3. c) It joins DNA fragments together.
4. d) It transcribes DNA into RNA.

Question:7 Recombinant DNA technology involves:

1. a) Combining DNA from different sources.
2. b) Cloning entire organisms.
3. c) Synthesizing DNA from scratch.
4. d) None of the above.

Question:8 What is the purpose of gene therapy?

1. a) To create genetically modified organisms.
2. b) To study the genetics of diseases.
3. c) To treat genetic disorders by replacing or repairing defective genes.
4. d) To clone animals for research purposes.

Question:9 The Green Revolution is associated with

1. a) Advances in information technology.
2. b) Innovations in transportation.
3. c) Agricultural improvements leading to increased food production.
4. d) Environmental conservation efforts.

Question:10 What is the significance of restriction enzymes in genetic engineering?

1. a) They facilitate DNA replication.
2. b) They cut DNA at specific recognition sequences.
3. c) They synthesize RNA from DNA templates.
4. d) They regulate gene expression

MCQs Answers

Question No	Answer	Question No	Answer
1	D	6	C
2	A	7	A
3	C	8	C
4	B	9	C
5	D	10	B