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NCERT Exemplar Class 12 Biology Solutions Chapter 12 Biotechnology and Its Applications

NCERT Exemplar Class 12 Biology Solutions Chapter 12 Biotechnology and Its Applications

Edited By Priyanka kumari | Updated on Aug 26, 2022 03:03 PM IST | #CBSE Class 12th

NCERT exemplar Class 12 Biology solutions chapter 12 - Biotechnology and its Application is a comparatively easy and interesting topic, as well as scoring from the point of view of exams. Various different professionals in this field have developed NCERT exemplar Class 12 Biology chapter 12 solutions that are easily understandable according to the examination guidelines given by CBSE. The experts have used the easiest yet the most precise method to solve questions that will help students to score in their examinations. The NCERT exemplar Class 12 Biology solutions chapter 12 pdf download is useful for quick access.

Introduction to NCERT Exemplar Solutions for Class 12 Biology Chapter 12 Biotechnology And Its Application

NCERT Exemplar Solutions for Class 12 Biology Chapter 12 Biotechnology And Its Application- Very Short Answer Type Questions:

Question:1

In view of the current food crisis, it is said that we need another green revolution. Highlight the major limitations of the earlier green revolution.

Answer:

Major limitations of the earlier Green Revolution are as follows:
(a) It was mainly based on better management of farm practices
(b) It involved the use of agrochemicals (pesticides and fertilizers); which has many side effects

Question:2

Expand GMO. How is it different from a hybrid

Answer:

GMO stands for Genetically Modified Organism. A hybrid is produced after crossing two different kinds of individuals, while a GMO is produced by alteration in the gene, which is carried out in vitro.

Question:3

Differentiate between diagnostics and therapeutics. Give one example and for each category.

Answer:

Diagnostics relate to finding a suspected disease while therapeutics relates to treatment. Serum analysis is a diagnostic procedure while administering antibiotic comes under the ambit of therapeutics.

Question:4

Give the full form of ELISA. Which disease can be detected using it? Discuss the principle underlying the test.

Answer:

ELISA stands for Enzyme-Linked Immunosorbent Assay. AIDS can be detected using this procedure. Antigen-antibody reaction is the underlying principle in this test.

Question:5

Can a disease be detected before its symptoms appear? Explain the principle involved.

Answer:

Detection of a disease before the appearance of symptoms is now possible by using biotechnology. PCR (Polymerase Chain Reaction) helps in doing this. Use of PCR can amplify the nucleic acids of bacteria or virus. This can help in detecting their presence even when they are in low concentration.

Question:6

Write a short note on Biopiracy highlighting the exploitation of developing countries by the developed countries.

Answer:

Biopiracy is the use of bio-resources by MNCs and other organizations without authorization from the countries and people. Some MNCs make some minor tweaking to get the patent on products or processes which have been under the domain of traditional knowledge of any country. By obtaining the patent, these companies get a license to exploit the worldwide market. This leaves the people (with traditional knowledge) at the losing end. Patent on turmeric by an American company is a good example of biopiracy. Turmeric is being used as an antiseptic in India since ages and hence is part of the traditional knowledge.

Question:7

Many proteins are secreted in their inactive form. This is also true of many toxic proteins produced by microorganisms. Explain how the mechanism is useful for the organism producing the toxin?

Answer:

When the toxin is present in an inactive form, it does not harm the organism, which produces the toxin. For example; B. thuringiensis produces an insecticidal toxin which does not kill this bacterium. This toxin becomes active when it enters alkaline pH of the gut of an insect and the insects killed in the process.

Question:8

While creating genetically modified organisms, genetic barriers are not respected. How can this be dangerous in the long run?

Answer:

When a genetically modified organism is introduced in the ecosystem, it can have dire consequences for the ecosystem. Thus, not respecting the genetic barriers (while creating genetically modified organisms) can have long-term repercussions on the ecosystem.

Question:9

Why has the Indian Parliament cleared the second amendment of the country's patents bill?

Answer:

It was observed that some MNCs or other organizations obtained a patent on products or services which had been part of the traditional knowledge of developing countries. This act had the potential of exploitation of indigenous people by not providing adequate compensation and by commercial exploitation.
To prevent such misuse of patent, the Indian Parliament cleared the second amendment of the country’s patent bill.

Question:10

Give any two reasons why the patent on Basmati should not have gone to an American Company.

Answer:

Following are the two reasons why the patent on Basmati should not have gone to an American Company:

  1. A total of 27 documented varieties of Basmati is being grown in India, and thus it is an integral part of traditional farm practices in India.
  2. The patent could have prevented Indian people from growing Basmati rice.

Question:11

How was Insulin obtained before the advent of rDNA technology? What were the problems encountered?

Answer:

Before the advent of rDNA technology, Insulin was mainly obtained from the pancreas of slaughtered animals. This often resulted in unwanted side effects on the users.

Question:12

Concerning understanding diseases, discuss the importance of transgenic animal models.

Answer:

Transgenic animals can serve as models to understand the progression of various disease in human. Transgenic models exist for many human diseases like cancer, cystic fibrosis, rheumatoid arthritis and Alzheimer’s. These animals can be observed to understand the causative gene for a particular disease. This can help in devising suitable treatment for some particular diseases.

Question:13

Name the first transgenic cow. Which gene was introduced in this cow?

Answer:

Rosie was the first transgenic cow, and it was produced in 1997. The gene for human protein alpha-lactalbumin was introduced in this cow. Thus, the cow could produce protein-enriched milk. This milk was nutritionally more balanced than natural cow milk.

Question:14

PCR is a useful tool for early diagnosis of an infectious disease. Elaborate.

Answer:

Use of PCR can amplify the nucleic acids of bacteria or virus. This can help in detecting their presence even when they are in low concentration. This helps in early detection of a disease which was not possible with conventional diagnostic tools. By the time, conventional diagnostic tools could detect a disease; it was very late because of the very high concentration of pathogens. Nevertheless, early detection by using PCR can help in timely and more efficient treatment.

Question:15

What is GEAC, and what are its objectives?

Answer:

The full form of GEAC is Genetic Engineering Approval Committee. The Government of India has formed this committee. Following are its main objectives:

  1. The validity of GM research.
  2. Assessing safety of introduction of GM products among the public.

Question:16

For which variety of Indian rice, the patent was filed by a USA Company?

Answer:

The patent was filed for Basmati rice.

Question:17

Discuss the advantages of GMO.

Answer:

Following are the advantages of GMO:

  1. GM crops are more tolerant to various stresses.
  2. GM crops reduce the reliance on pesticides and synthetic fertilizers.
  3. GM crops can enhance the nutrient value of a particular food.

Short Answer Type Questions:

Question:1

Gene expression can be controlled with the help of RNA. Explain the method with an example.

Answer:

Gene expression can be controlled with the help of RNA interference (RNAi). RNAi takes place in all eukaryotic organisms and is part of the cellular defence. Under this method, a complementary dsRNA binds to, prevents translation of mRNA (silencing), and thus silences a specific mRNA. Thus gene expression which could have been carried out by the mRNA does not happen.
This method has been used to encounter a nematode in plants. Agrobacterium is used as a vector to introduce nematode specific gene into the host plant. The introduction of DNA results in the production of sense and antisense RNA in the host cells. These two RNAs form dsRNA and silence the specific mRNA.

Question:2

Ignoring our traditional knowledge, can we prove costly in the area of biological patenting? Justify.

Answer:

Traditional knowledge accumulates over thousands of generations. It carries the knowledge of cost-effective ways to tackle many problems related to human life. A patent is granted to a new product or service, which is based on an entirely novel or new concept. Once an organization or an individual obtains a patent for a particular product or service, it gets the sole right to reap commercial benefits from that product or service.
In most of the cases, the patent holder tends to overexploit the market during the patent period. If we used traditional knowledge instead, it would help us in saving a lot of money. This shows that ignoring our traditional knowledge can prove costly in the area of biological patenting.

Question:3

Highlight any four areas where genetic modification of plants has been useful.

Answer:

Genetic modification of plants has been useful in the following areas:

  1. Increased tolerance to abiotic stress (drought, salinity, high temperature, etc.)
  2. Increased tolerance to biotic stress; like pests and weeds.
  3. Increased efficiency of mineral usage from the soil.
  4. Enhanced nutritional value.

Question:4

What is a recombinant DNA vaccine? Give two examples.

Answer:

A vaccine, which is prepared by using recombinant DNA technology, is called an rDNA vaccine. Enzo Paolette and Dennis Panicali from New York State Department of Health were able to transform smallpox vaccine so that it could be effective against some other diseases.
Thus, they were the pioneers in making rDNA vaccine. Hepatitis B vaccine and the HPV vaccine are two examples of rDNA vaccines.

Question:5

Why is it that the line of treatment for a genetic disease is different from infectious diseases?

Answer:

An infectious disease happens because of some pathogen. The line of treatment in such condition is focused on eliminating the causative pathogen from the body. However, a genetic disease happens because of some anomaly in the genotype.
No antibiotic has an effect on genotype anomaly. Hence, the line of treatment for a genetic disease is entirely different from infectious disease.

Question:6

Discuss briefly how a probe is used in molecular diagnostics.

Answer:

For molecular diagnostics: a single strand DNA or RNA is tagged with a radioactive probe. It is then introduced into the host cell and allowed to hybridize with its complementary DNA in a clone of cells which are formed in vitro. The cloned cells are then observed using radiography. This helps in detecting the problems.

Question:7

Who was the first patient who was given gene therapy? Why was the given treatment recurrent in nature?

Answer:

A four-year-old girl was the first patient to be given gene therapy. She was suffering from adenosine deaminase (ADA) deficiency, and this therapy was given in 1990. The treatment with gene therapy involves manipulating the DNA of lymphocytes from the patient’s body.
The modified lymphocytes are grown in vitro and then infused into the patient’s body. We know that lymphocytes are not immortal, but they have a definite life span. Due to this, this treatment is recurrent in nature.

Question:8

Taking examples under each category, discuss upstream and downstream processing

Answer:

Upstream processing: This involves identifying a material, which can be transformed for making the final product. Let us take the example of making BT cotton. In this, extracting the gene for insecticide toxin from B. thuringiensis is an example of upstream processing. Similarly, introducing this gene into cotton is an upstream process.

Downstream processing: This involves suitable purification and isolation of the final product. Let us take that example of fermentation to understand this. Purification of alcohol through distillation is part of downstream processing.

Question:9

Define Antigen and Antibody. Name any two diagnostic kits based upon them.

Answer:

Antigen: A foreign substance, which elicits an immune response from the body, is called an antigen.
Antibody: A protein, which is synthesized in response to an antigen in the body, is called an antibody.
Two diagnostic kits; based on antigen and antibody are as follows:
(a) ELISA kit
(b) Pregnancy test kit

Question:10

ELISA technique is based on the principles of antigen-antibody interaction. Can this technique be used in the molecular diagnosis of a genetic disorder, such as phenylketonuria?

Answer:

Yes. One can use an antibody against the enzyme (that is responsible for the metabolism of phenylalanine) to develop ELISA based is a diagnostic technique. The patient where the enzyme protein is absent would give a negative result in ELISA when compared to a normal individual.

Question:11

How is a mature, functional insulin hormone different from its prohormone form?

Answer:

Insulin in its prohormone form is not active and it needs to be mature to become the functional Insulin. The prohormone form of Insulin contains an extra stretch of a polypeptide called C peptide. When Insulin becomes mature, it is devoid of C peptide.

Question:12

Gene therapy is an attempt to correct a genetic defect by providing a normal gene into the individual. By this, the normal function can be restored. An alternate method would be to provide the gene product (protein/enzyme) known as enzyme replacement therapy, which would also restore the function. Which is your opinion is a better option? Give a reason for your answer.

Answer:

Enzyme replacement therapy works on artificially administering the required enzyme into the patient’s body. This helps in the management of the disease. However, this needs frequent re-administration of enzyme and other necessary drugs to continue the therapy. In most of the cases, the therapy is costly and is a cause of financial and emotional drain on the patient. Using gene correction is a permanent solution. For example, a person with ADA deficiency can be permanently cured if the required gene is introduced during the embryo stage. This will ensure a better quality of life for the patient.

Question:13

Transgenic animals are the animals in which a foreign gene is expressed. Such animals can be used to study the fundamental biological process, a phenomenon as well as for producing products useful for mankind. Give one example for each type.

Answer:

Following are the examples of various uses of transgenic animals:
(a) Fundamental biological processes: Transgenic animals can be used to understand insulin-like growth factors in humans:
(b) Study of Diseases: Many transgenic animals are introduced with genes for a certain disease. Then progression and possible cure for such disease can be studied using these animals.
(c) Biological Products: A transgenic cow Rosie could produce protein-enriched milk

Question:14

When a foreign DNA is introduced into an organism, how is it maintained in the host and how is it transferred to the progeny of the organism?

Answer:

When a foreign DNA is introduced into an organism, it binds with the chromosome of the host organism because of recombination. When progeny of the host organism is produced (through sexual or asexual reproduction), the new gene is passed on to the progeny because of inheritance. This is similar to any defective gene being passed on from one generation to the next generation.

Question:15

Bt cotton is resistant to pests, such as lepidopteron, dipterans and coleopterans. Is BT cotton also resistant to other pests as well?

Answer:

The genes from Bacillus thuringiensis are pest-specific. This means that they are highly effective against a select group of pests but do not harm other insects. As a corollary, Bt cotton is not resistant to other pests. This is, in fact, an advantage from the perspective of maintaining biodiversity in the environment. Beneficial insects are saved from harm because farming of Bt cotton does not need the use of pesticides.

Long Answer Type Questions:

Question:1

A patient is suffering from ADA deficiency. Can he be cured? How?

Answer:

A person suffering from ADA deficiency can be cured by various methods which are discusses below:
(a) Bone Marrow Transplantation: This is a costly and risky surgical procedure. It requires a suitable donor, which is difficult to find. An identical twin is supposed to be the best donor because chances of tissue rejection are very high in bone marrow transplantation.
(b) Enzyme Replacement Therapy: Enzyme replacement therapy is based on administering the missing enzyme to the patient by injection. This involves recurrent treatment that has escalated the cost this therapy.
(c) Gene Therapy: Gene therapy involves taking out the lymphocytes from the patient’s blood. Then are lymphocytes are genetically engineered to add the missing gene. Recombinant lymphocytes are grown in a suitable medium and then administered to the patient. This too is not a permanent cure because lymphocytes have a certain lifespan. The patient needs to be administered lymphocytes after frequent intervals. However, the gene isolated from marrow cells producing ADA is introduced into cells at early embryonic stage could be a permanent cure for this disease.

Question:2

Define transgenic animals. Explain in detail any four areas where they can be utilized.

Answer:

Transgenic animals are the animals in which a foreign gene is expressed. Transgenic rats, pigs, cows, rabbits, sheep, and fish have been produced. However, more than 95% of all transgenic animals are mice. Four areas in which transgenic animals can be utilized are as follows:
(a) Fundamental Biological Processes: Transgenic animals can be used to understand insulin-like growth factors in humans: A particular factor can be introduced from another animal, and then the behaviour of this factor can be studied in the transgenic animal.
(b) Study of Diseases: Many transgenic animals are introduced with genes for a certain disease. Then progression and possible cure for such disease can be studied using these animals. Today,
models of transgenic animals exist in which cancer, cystic fibrosis, rheumatoid arthritis, etc. can be studied.
(c) Biological Products: A transgenic cow Rosie could produce human protein-enriched milk. This milk contains 2.4 g of human alpha-lactalbumin per litre. This milk is nutritionally balanced for babies than normal cow milk.
(d) Vaccine Safety: Before approval for use in humans, any vaccine needs to prove its safety on model animals. For example, transgenic mice have been used to study the safety of polio vaccine.

Question:3

You have identified a useful gene in bacteria. Make a flow chart of the steps that you would follow to transfer this gene to a plant.

Answer:

Following are the steps for transferring the useful gene to a plant.
(a) Isolation of useful gene using Restriction Endonucleases
(b) Transferring the gene to a suitable vector to create a recombinant DNA molecule
(c) Transfer of these recombinant DNA molecules to the target cells
(d) Screening of cells for transformation
(e) Selection of transformed cells
(f) Regeneration of plants from the transformed cells to get transgenic plants.

Question:4

Highlight five areas where biotechnology has influenced our lives.

Answer:

(a) Food Security: The earlier Green Revolution has certain limitations. Biotechnology can help in overcoming those limitations. It can help in improving food production to meet the growing demand because of a growing population. Production of Spirulina is an example, which shows that a huge quantity of nutrient can be produced by minimum use of land.
(b) Medicine: Many vaccines and other pharmaceuticals products have been made through biotechnology. Several diagnostic techniques; using biotechnology; has made it easier to diagnose a disease in time and has helped in better cure.
(c) Environmental Protection: Use of Bt cotton helps in minimizing the use of pesticides. This is beneficial for the environment because it helps in saving useful insets.
(d) Crime Detection: DNA fingerprinting can be used to trace the identity of a criminal by using even the smallest remains of criminal’s body parts.
(e) Legal Disputes: Parentage disputes are being settled with the use of DNA fingerprinting.

Question:5

What are the various advantages of using genetically modified plants to increase the overall yield of the crop?

Answer:

Advantage of using GM plants are as follows:

  1. GM crops are more tolerant to abiotic stresses, like drought, salinity, high temperature, etc. Thus, GM modified crops can also be grown in areas which are not ideal for cultivation.
  2. GM crops reduce the need for chemical pesticides. This helps in saving many useful insects which otherwise get killed by chemical pesticides. It is important to remember that many insects facilitate pollination in crops.
  3. Mineral usage by a plant is more efficient in case of GM crops. This prevents early exhaustion of soil nutrients.
  4. GM crops can have enhanced nutritional value. For example, golden rice is fortified with vitamin A. Similarly, the carrot has been fortified with iron.

GM crops can be tailor-made to provide alternate resources to industries, such as starch or fuel.

Question:6

Explain with the help of one example of how genetically modified plants can:
(a) Reduce the usage of chemical pesticides
(b) Enhance the nutritional value of food crops

Answer:

(a) Bt cotton contains the gene, which has a pesticidal role. This gene is pest-specific and affects only certain pests. By encountering most of the common pests of cotton, Bt cotton minimizes the use of chemical pesticides.
(b) Biofortification involves the addition of nutrients through genetic engineering. This can also be achieved through conventional breeding methods. Biofortification is beneficial because a plant product has inbuilt extra nutrient in it. This means that nutrients need not be added at the processing stage. This can help in tackling hidden hunger among the poor. Golden rice is an example of rice, which has been fortified with vitamin A.

Question:7

List the disadvantages of Insulin obtained from the pancreas of slaughtered cows and pigs:

Answer:

Following are the disadvantages of Insulin from slaughtered animals:
(a) Demand for Insulin is very high, which necessitates slaughtering of a large number of animals.
(b) Slaughtering of animals amounts to cruelty against animals.
(c) Insulin from animal origin can result in allergic reactions because of the body’s tendency to encounter foreign substance.
(d) The slaughtered animal can be infected with some dangerous microbes. This can contaminate the Insulin.

Question:8

List the advantages of recombinant Insulin.

Answer:

Following are the advantages of recombinant Insulin:
(a) Recombinant Insulin can be prepared on a large scale without worrying about the source animal.
(b) Batch to batch consistency can be maintained, and quality can be maintained.
(c) Helps in preventing cruelty against animals.
(d) Chances of allergic reactions have been minimized.
(e) Chances of transmission of infection from source animals have been nullified.
(f) Recombinant Insulin has almost replaced animal-sourced Insulin from around the world.
(g) This paves the way for forms of Insulin, which need not be given through injections.

Question:9

What is meant by the term bio-pesticide? Name and explain the mode of action of a popular bio-pesticide.

Answer:

A biological agent, which works as a pesticide, is called biopesticide. Biopesticides can be of following types:
(a) Microbial: Many Bacteria and fungi have pesticidal properties.
(b) Herbal: Some plants; like neem and canola can help in controlling pesticides.
(c) Plant Incorporated Protectants: These are incorporated into the genes of a plant through genetic engineering. Bt cotton is an example of a plant with the incorporated pesticidal property.
Bacillus thuringiensis affects the pests of Lepidoptera, Coleoptera and Diptera. It is a well-known example of microbial pesticide. A gene in B. thuringiensis produces a toxin, which remains inactive in the bacterium. Once this toxin enters the gut of the pest; the Alkaline pH makes it active. The toxin results in perforations in the gut of the pest, and eventually, the pest is killed. This gene has been incorporated in Bt cotton, Bt tomato, Bt brinjal, etc. These GM crops are giving good results.

Question:10

Name the five key tools for accomplishing the tasks of recombinant DNA technology. Also, mention the functions of each tool.

Answer:

Key tools in rDNA technology
(a) Restriction endonuclease.
(b) Gel electrophoresis
(c) Ligase enzyme
(d) DNA delivery system

Functions

  1. Cutting the desired DNA at desired locations
  2. Separating the desired DNA fragments.
  3. Creating recombinant DNA molecule
  4. To introduce gene in the host

Multiple Choice Questions:

Question:1

BT cotton is not:
a. A GM plant
b. Insect-resistant
c. A bacterial gene expressing system
d. Resistant to all pesticides

Answer:

The answer is the option (d) Resistant to all pesticides
Explanation: (d) Resistant to all pesticides because of the gene incorporated from Bacillus thuringiensis.

Question:2

C-peptide of human Insulin is:
a. A part of mature insulin molecule
b. Responsible for formation of disulphide bridges
c. Removed during maturation of pro-insulin to insulin
d. Responsible for its biological activity

Answer:

c). Removed during maturation of pro-insulin to insulin
The connecting peptide or C-peptide is a short protein containing 31 amino acids. It connects the A and B chain of proinsulin molecule. After the processing of proinsulin molecule, C-peptide is removed leaving behind A and B chains which bound together by disulphide bonds to constitute an insulin molecule.

Question:3

GEAC stands for:
a. Genome Engineering Action Committee
b. Ground Environment Action Committee
c. Genetic Engineering Approval Committee
d. Genetic and Environment Approval committee

Answer:

The answer is the option (c) Genetic Engineering Approval Committee
Explanation: (c) Genetic Engineering Approval Committee that permits research work in genetics.

Question:4

α -1 antitrypsin is:

a. An antacid
b. An enzyme
c. Used to treat arthritis
d. Used to treat emphysema

Answer:

The answer is the option (d) Used to treat emphysema
Explanation: (d) Used to treat emphysema

Question:5

A probe which is a molecule used to locate homologous sequences in a mixture of DNA or RNA molecules could be:
a. An ssRNA
b. An ssDNA
c. Either RNA or DNA
d. Can be ssDNA but not ssRNA

Answer:

The answer is the option (c) either RNA or DNA
Explanation: (c) either RNA or DNA

Question:6

Choose the correct option regarding Retrovirus:
a. An RNA virus that synthesizes DNA during infection
b. A DNA virus that synthesizes RNA during infection
c. An ssDNA virus
d. A dsRNA virus

Answer:

The answer is the option (a) An RNA virus that can synthesize DNA during infection
Explanation: A retrovirus is a single-stranded positive sense RNA virus with a DNA intermediate in addition, as an obligate parasite, targets a host cell.

Question:7

The site of production of ADA in the body is:
a. Erythrocytes
b. Lymphocytes
c. Blood plasma
d. Osteocytes

Answer:

The answer is the option (b) Lymphocytes
Explanation: (b) Lymphocytes are involved in secretion of ADA.

Question:8

A protoxin is:
a. A primitive toxin
b. A denatured toxin
c. The toxin produced by protozoa
d. Inactive toxin

Answer:

The answer is the option (d) Inactive toxin
Explanation: For example, BT toxin protein exists as inactive protoxin but becomes active due to the pH of gut once it is inside the gut of the insect.

Question:9

Pathophysiology is the:
a. Study of physiology of pathogen
b. Study of the normal physiology of host
c. Study of altered physiology of host
d. None of the above

Answer:

The answer is the option (c) Study of altered physiology of host
Explanation: Pathophysiology is a combination of pathology and physiology. While physiology is about various biological processes, pathology is about diseased state.

Question:10

The trigger for activation of the toxin of Bacillus thuringiensis is:
a. Acidic pH of stomach
b. High-temperature
c. Alkaline pH of gut
d. Mechanical action in the insect gut

Answer:

The answer is the option (c) Alkaline pH of gut
Explanation: Alkaline pH of gut of insects converts inactive protoxin into active toxin. This kills the insect.

Question:11

Golden rice is:
a. A variety of rice grown along the yellow river in China
b. Long stored rice having yellow colour tint
c. A transgenic rice having the gene for β – carotene
d. The wild variety of rice with yellow coloured grains

Answer:

The answer is the option (c) A transgenic rice having gene for beta-carotene
Explanation: (c) A transgenic rice having gene for beta-carotene is called golden rise due to its color.

Question:12

In RNAi, genes are silenced using:
a. ss DNA
b. ds DNA
c. ds RNA
d. ss RNA

Answer:

The answer is the option (c) ds RNA
Explanation: (c) ds RNA

Question:13

The first clinical gene therapy was done for the treatment of:

a. AIDS
b. Cancer
c. Cystic fibrosis
d. SCID (Severe Combined Immuno Deficiency resulting from deficiency of ADA)

Answer:

The answer is the option (d) SCID (Servere Combined Immuno Deficiency resulting from deficiency of ADA)
Explanation: The first clinical gene therapy was given in 1990 to a 4-year old girl with adenosine deaminase (ADA) deficiency.

Question:14

ADA is an enzyme which is deficient in a genetic disorder SCID. What is the full form of ADA?
a. Adenosine deoxyaminase
b. Adenosine deaminase
c. Aspartate deaminase
d. Arginine deaminase

Answer:

The answer is the option (b) Adenosine deaminase
Explanation: (b) Adenosine deaminase commonly called ADA.

Question:15

Silencing of a gene could be achieved through the use of:
a. RNAi only
b. antisense RNA only
c. both RNAi and antisense RNA
d. none of the above

Answer:

The answer is the option (c) both RNAi and antisense RNA
Explanation: (c) both RNAi and antisense RNA

The chapter 12 of NCERT Class 12 Biology Solutions deals with a different and new emerging field of biotechnology and its application in a variety of fields mainly focusing on agriculture and medicines. Biotechnology has been rapidly used in different fields and its growth has aided various other branches of research in an environment-friendly way.

The NCERT exemplar Class 12 Biology chapter 12 solutions teaches about production of different biological products that further help in research and production of genetically modified animals, plants and microbes.

Class 12 Biology NCERT exemplar solutions chapter 12 shows the application of new developed biotechnology through new conventional methods in an ecological manner that can easily be done genetically modified organisms or transgenic organisms.

Major Subtopics in NCERT Exemplar Class 12 Biology Solutions Chapter 12 Biotechnology And Its Application:

  • Biotechnological Applications in Agriculture
  • Biotechnological Applications in Medicine
  • Genetically Engineered Insulin
  • Gene Therapy
  • Molecular Diagnosis
  • Transgenic Animals
  • Normal physiology and development
  • Study of disease
  • Biological products
  • Vaccine safety
  • Chemical safety testing
  • Ethical Issues

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NCERT Exemplar Class 12 Biology Solutions Chapter 12 – Learning Outcomes:

  • Through Class 12 Biology NCERT exemplar solutions chapter 12 the students will learn about new methods and procedures used in different fields through development in biotechnology and how such development is used in various fields of medicine, pharmaceutical, and food production.
  • In NCERT exemplar Class 12 Biology solutions chapter 12, the students will learn about the latest developments done under biotechnology that safeguards and solves various environmental issues through developments in the biotechnological field.
  • The chapter focuses on all the important methods of biotechnology employed in the field of agriculture including organic agriculture, agrochemical agriculture, and genetically tampered agriculture, along with production of medicines through recombinant DNA procedures concluding with the ethical problems faced in manipulating the natural characteristics of various plants and animals.
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Importance of NCERT Exemplar Class 12 Biology Solutions Chapter 12 Biotechnology And Its Application:

  • From marks scoring point of view, the chapter covers various different methods and procedures developed in the field of biotechnology to aid better production and advancement in the medicinal and agricultural sector.
  • In NCERT exemplar solutions for Class 12 Biology chapter 12, some of the important topics to focus on are different methods and application of biotechnology in agriculture through different genetically manipulated organisms, gene therapy, molecular diagnosis and genetically engineered insulin to aid growth in the field of medicine.
  • NCERT exemplar Class 12 Biology solutions chapter 12 covers different methods of development that has helped and eased the production and research work in medicines and agriculture through DNA manipulation and genetically engineered differences to aid different crops, and medicines in an ecological manner.
  • The chapter also deals with issues arising out of and DNA manipulation of different plants and animals to aid developments and how these are considered harmful by some people, whereas how this development in biotechnology is encouraged to promote growth.
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1. 1. What are important topics of NCERT exemplar Class 12 Biology solutions chapter 12?

Some of the most important topics to be covered by the student keeping in mind the Board examination are application of biotechnology in agriculture through different genetically manipulated organisms, gene therapy, molecular diagnosis and genetically engineered insulin to aid growth in the field of medicine along with ethical issues associated with it.

2. 2. Are the NCERT exemplar Class 12 Biology solutions chapter 12 helpful for exams?

Yes, the solutions provided here for the NCERT questions are true and apt in order to teach the students about the correct way to answer questions for their Board exams prepared by professionals according to the guidelines provided by CBSE.

3. 3. Is the study material accessible online and offline both?

Yes, our site provides free access to NCERT Exemplar Class 12 Biology chapter 12 solutions for students online and they can even access offline by downloading it using webpage to pdf tools which are available online at no cost.

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Questions related to CBSE Class 12th

Have a question related to CBSE Class 12th ?

hello mahima,

If you have uploaded screenshot of your 12th board result taken from CBSE official website,there won,t be a problem with that.If the screenshot that you have uploaded is clear and legible. It should display your name, roll number, marks obtained, and any other relevant details in a readable forma.ALSO, the screenshot clearly show it is from the official CBSE results portal.

hope this helps.

Hello Akash,

If you are looking for important questions of class 12th then I would like to suggest you to go with previous year questions of that particular board. You can go with last 5-10 years of PYQs so and after going through all the questions you will have a clear idea about the type and level of questions that are being asked and it will help you to boost your class 12th board preparation.

You can get the Previous Year Questions (PYQs) on the official website of the respective board.

I hope this answer helps you. If you have more queries then feel free to share your questions with us we will be happy to assist you.

Thank you and wishing you all the best for your bright future.

Hello student,

If you are planning to appear again for class 12th board exam with PCMB as a private candidate here is the right information you need:

  • No school admission needed! Register directly with CBSE. (But if you want to attend the school then you can take admission in any private school of your choice but it will be waste of money)
  • You have to appear for the 2025 12th board exams.
  • Registration for class 12th board exam starts around September 2024 (check CBSE website for exact dates).
  • Aim to register before late October to avoid extra fees.
  • Schools might not offer classes for private students, so focus on self-study or coaching.

Remember , these are tentative dates based on last year. Keep an eye on the CBSE website ( https://www.cbse.gov.in/ ) for the accurate and official announcement.

I hope this answer helps you. If you have more queries then feel free to share your questions with us, we will be happy to help you.

Good luck with your studies!

Hello Aspirant , Hope your doing great . As per your query , your eligible for JEE mains in the year of 2025 , Every candidate can appear for the JEE Main exam 6 times over three consecutive years . The JEE Main exam is held two times every year, in January and April.

Hi there,

Hope you are doing fine

Yes you are certainly eligible for giving the jee exam in the year 2025. You must pass the maths exam with at least 75% criteria as required by jee and provide the marksheet and the passing certificate while registering for the exam.


Pursuing maths as an additional subject while taking biology as your main subject does not offer any hindrance in you appearing for the jee examination. It is indeed an privilege to pursue both maths and biology as the subjects and prepare for the same.

There will be no issue in filling the form while registering for the exam as it will only require your basic details and marksheet which you can provide by attaching the marksheet of maths also. Also, a detailed roadmap is also available on the official websites on how to fill the registration form. So you can fill the form easily.


Hope this resolves your query.

View All

A block of mass 0.50 kg is moving with a speed of 2.00 ms-1 on a smooth surface. It strikes another mass of 1.00 kg and then they move together as a single body. The energy loss during the collision is

Option 1)

0.34\; J

Option 2)

0.16\; J

Option 3)

1.00\; J

Option 4)

0.67\; J

A person trying to lose weight by burning fat lifts a mass of 10 kg upto a height of 1 m 1000 times.  Assume that the potential energy lost each time he lowers the mass is dissipated.  How much fat will he use up considering the work done only when the weight is lifted up ?  Fat supplies 3.8×107 J of energy per kg which is converted to mechanical energy with a 20% efficiency rate.  Take g = 9.8 ms−2 :

Option 1)

2.45×10−3 kg

Option 2)

 6.45×10−3 kg

Option 3)

 9.89×10−3 kg

Option 4)

12.89×10−3 kg

 

An athlete in the olympic games covers a distance of 100 m in 10 s. His kinetic energy can be estimated to be in the range

Option 1)

2,000 \; J - 5,000\; J

Option 2)

200 \, \, J - 500 \, \, J

Option 3)

2\times 10^{5}J-3\times 10^{5}J

Option 4)

20,000 \, \, J - 50,000 \, \, J

A particle is projected at 600   to the horizontal with a kinetic energy K. The kinetic energy at the highest point

Option 1)

K/2\,

Option 2)

\; K\;

Option 3)

zero\;

Option 4)

K/4

In the reaction,

2Al_{(s)}+6HCL_{(aq)}\rightarrow 2Al^{3+}\, _{(aq)}+6Cl^{-}\, _{(aq)}+3H_{2(g)}

Option 1)

11.2\, L\, H_{2(g)}  at STP  is produced for every mole HCL_{(aq)}  consumed

Option 2)

6L\, HCl_{(aq)}  is consumed for ever 3L\, H_{2(g)}      produced

Option 3)

33.6 L\, H_{2(g)} is produced regardless of temperature and pressure for every mole Al that reacts

Option 4)

67.2\, L\, H_{2(g)} at STP is produced for every mole Al that reacts .

How many moles of magnesium phosphate, Mg_{3}(PO_{4})_{2} will contain 0.25 mole of oxygen atoms?

Option 1)

0.02

Option 2)

3.125 × 10-2

Option 3)

1.25 × 10-2

Option 4)

2.5 × 10-2

If we consider that 1/6, in place of 1/12, mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of a substance will

Option 1)

decrease twice

Option 2)

increase two fold

Option 3)

remain unchanged

Option 4)

be a function of the molecular mass of the substance.

With increase of temperature, which of these changes?

Option 1)

Molality

Option 2)

Weight fraction of solute

Option 3)

Fraction of solute present in water

Option 4)

Mole fraction.

Number of atoms in 558.5 gram Fe (at. wt.of Fe = 55.85 g mol-1) is

Option 1)

twice that in 60 g carbon

Option 2)

6.023 × 1022

Option 3)

half that in 8 g He

Option 4)

558.5 × 6.023 × 1023

A pulley of radius 2 m is rotated about its axis by a force F = (20t - 5t2) newton (where t is measured in seconds) applied tangentially. If the moment of inertia of the pulley about its axis of rotation is 10 kg m2 , the number of rotations made by the pulley before its direction of motion if reversed, is

Option 1)

less than 3

Option 2)

more than 3 but less than 6

Option 3)

more than 6 but less than 9

Option 4)

more than 9

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