Please refer to Biotechnology and its Application Class 12 Biology Important Questions with answers below. These solved questions for Chapter 12 Biotechnology and its Application in NCERT Book for Class 12 Biology have been prepared based on the latest syllabus and examination guidelines issued by CBSE, NCERT, and KVS. Students should learn these solved problems properly as these will help them to get better marks in your class tests and examinations. You will also be able to understand how to write answers properly. Revise these questions and answers regularly. We have provided Notes for Class 12 Biology for all chapters in your textbooks.

Important Questions Class 12 Biology Chapter 12 Biotechnology and its Application

All Biotechnology and its Application Class 12 Biology Important Questions provided below have been prepared by expert teachers of Standard 12 Biology. Please learn them and let us know if you have any questions.

Read the following passage and answer the questions from 46 to 50 given below.
Transgenic cows have extra gene or genes inserted into their DNA. Firstly the genes for the desired product is identified and sequenced.
Then a gene construct containing this desired gene is introduced into female cow cells.
Transgenic bovine cells are selected and fused with bovine oocytes that have had all of their chromosomes removed. Once fused with the oocyte, the transgenic cells chromosomes are
reprogrammed to direct development which can be implanted into a recipient cow. The resulting transgenic cow only express the transgene in her milk. This is because expression of the transgene is controlled by a promoter specific to lactating mammary cells.

Question. Transgenic cow is produced through the implantation of ________ containing transgene into recipient cow.
(a) ova
(b) embryo
(c) mammary cell
(d) both (a) and (b)
Answer : B

Question. Production of transgenic cow fulfill the objective of
(a) increased milk production
(b) increased meat production
(c) molecular farming
(d) all of these.
Answer : D

Question. The name of first transgenic cow is
(a) Tracy
(b) Dolly
(c) Rosie
(d) ANDI.
Answer : C

Question. The gene construct with desired gene is introduced into female cow cells by
(a) transformation
(b) transduction
(c) transfection
(d) transplantation.
Answer : C

Question. Read the given statements and select the correct option.
Statement I : Transgenes only express in the mammary glands of transgenic cow.
Statement II : Transgenes are present in chromosomes of every cell in transgenic cow.
(a) Both statements I and II are true.
(b) Both statements I and II are false.
(c) Statement I is true but statement II is false.
(d) Statement I is false but statement II is true.
Answer : A

Assertion & Reasoning Based MCQs

For question numbers 51-60, two statements are given-one labelled Assertion and the other labelled Reason.
Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Assertion is false but reason is true.

Question. Assertion : Molecular probes are available for diagnosing genetic disorders, e.g., Duchenne muscular dystrophy, cystic fibrosis, Tay-sach’s disease.
Reason : The molecular probes are usually double stranded pieces of DNAs, labelled with radioisotopes such as 32P.
Answer : C

Question. Assertion : Genetically modified microbes help in crop protection.
Reason : Transgenic bacteria control insects by producing endotoxins.
Answer : B

Question. Assertion : Flavr-Savr tomato was the first transgenic commercial crop that entered the market.
Reason : Roundup variety of soybean was prepared through breeding.
Answer : C

Question. Assertion : Biopatents are awarded for biological entities and all products derived from them.
Reason : Patent on use of turmeric in wound healing was cancelled in 2008.
Answer : C

Question. Assertion : ADA deficiency cannot be cured permanently by gene therapy.
Reason : The lymphocytes from the blood of patient are grown in culture outside the body.
Answer : D

Very Short Answer Type Questions

Question. Give an example of bioweapon.
Answer : Bacillus anthracis

Question. State the role of C peptide in human insulin.
Answer : The C-peptide joins the A-peptide with B-peptide in the proinsulin. It is not present in mature insulin and is removed during processing of proinsulin to insulin.

Question. Name two transgenic microorganisms that have been used for large scale production of amino acids.
Answer :  Two transgenic microorganisms used for large scale amino acid production are: (i) Bacillus amyloliquefaciens (ii) Lactobacillus casei

Question. Name the cry genes that control cotton bollworm and corn borer respectively.
Answer :  The genes cryIAc and cryIIAb control the cotton bollworms, whereas cryIAb controls corn borer.

Question. What was the speciality of the milk produced by the transgenic cow Rosie ?
Answer : The first transgenic cow, Rosie produced human protein enriched milk which contained the human alpha lactalbumin and was nutritionally more balanced product for human babies than natural cow milk.

Short Answer Type Questions

Question. Biopiracy should be prevented. State why and how?
Answer : Some multinational companies of industrialised nations have a good economic status but are poor in biodiversity and are exploiting biodiversity of developing and underdeveloped countries without authorisation and proper compensation. There has been growing realisation of the injustice, inadequate compensation and benefit sharing between developed and developing countries. Therefore, some nations are developing laws to prevent such unauthorised exploitation of their bioresources and traditional knowledge.

Question. Explain the various steps involved in the production of artificial insulin.
Answer : The steps involved in the production of artificial insulin or humulin are as follows: (i) Isolation of donor or DNA segment – A useful DNA segment is isolated from the donor organism. (ii) Formation of recombinant DNA (rDNA) – Both the vector and donor DNA segments are cut in the presence of restriction endonuclease. In the presence of ligase DNA segments of both are joined to form rDNA. (iii) Production of multiple copies of rDNA – In this process multiple copies of this recombinant DNA are produced. (iv) Introduction of rDNA in the recipient organism – The rDNA is inserted into a recipient organism. (v) Screening of the transformed cells – The recipient (host) cells are screened in the presence of rDNA and the product of donor gene. The transformed cells are separated and multiplied.

Question. What are transgenic animals? Give an example.
Answer : Transgenic animals are those animals which contain in their genome, a foreign gene introduced by recombinant DNA technology. Such gene is called transgene. Examples of transgenic animals are transgenic mice and transgenic rabbit etc.

Question. Diagrammatically show steps involved in RNA interference.
Answer : The steps in RNA interference (RNAi)

Question. Write the full form of ELISA. Give an example of the clinical application of ELISA test.
Answer : Enzyme-linked immunosorbent assay (ELISA) is a non isotopic immunoassay. ELISA is based on the immunochemical principles of antigen-antibody reaction. ELISA is used for determining small quantity of proteins (hormones, antigens and antibodies). ELISA is also used for diagnosis of HIV. 

Question. Why do lepidopterans die when they feed on Bt cotton plant? Explain how does it happen.
Answer :  Bt cotton plant contains Bacillus thuringiensis, which produces Bt toxin, an insecticidal protein. This Bt toxin protein exist as inactive form but once an insect ingest the inactive toxin, it is converted into active form of toxin due to alkaline pH of the insects gut which solublise the crystals. The activated toxin binds to surface of midgut epithelial cells and creates pores that cause cell swelling and lysis and causes the death of the insect.

Question. How is the Bt cotton plant created as a GM plant? How is it protected against bollworm infestation?
Answer : Two genes cryIAc and cryIIAb control cotton bollworms. These two genes were isolated from Bacillus thuringiensis and incorporated into cotton plant. The genetically modified plant is called Bt cotton as it contains Bt toxin genes. The bacterium Bacillus thuringiensis produces Bt toxin proteins in mature form. When the insect larvae ingest any plant part, toxin becomes active in the alkaline pH of the gut and kills the insect pests. That is how Bt cotton attains resistance against bollworm.

Question. What is special of “Flavr Savr” variety of tomato ? Why is it preferred to its normal native variety ?
Answer : Flavr Savr, a variety of tomato is a genetically modified plant. In this variety one gene, which produces polygalactouronase enzyme is inactivated. The non availability of this enzyme prevents over ripening. Thus, fruit remains fresh for long time and it also retains flavour, superior taste and higher quantity of total soluble solids. So it prevents post harvest and over ripening losses. Thus, it is preferred over normal native variety.

Question. Explain how b-carotene rich rice varieties are produced.
Answer : Golden rice is a transgenic variety of rice (Oryza sativa) which contains good quantities of b-carotene (provitamin A-inactive state of vitamin A). b-carotene is a principal source of vitamin A. Since the grains (seeds) of the rice are yellow in colour due to b-carotene, the rice is commonly called golden rice. b-carotene (provitamin A) is converted into vitamin A. Thus, golden rice is rich in vitamin A. It is required by all individuals as it is present in retina of eyes. Deficiency of vitamin A causes night blindness and skin disorder. Since the contents of vitamin A are very low in rice, vitamin A is synthesised from b-carotene which is precursor of vitamin A. Prof. Ingo Potrykus and Peter Beyer produced genetically engineered rice by introducing three genes associated with synthesis of carotene. The grains (seeds) of transgenic rice are rich in provitamin.

Question. What is the full form of GEAC? Describe the main objectives of GEAC set up by the Indian government.
Answer : GEAC is Genetic Engineering Approval Committee. It makes decisions regarding the validity of GM research and the safety of introducing GM organisms for public services. The objectives of setting up GEAC by our government is as follows: (i) To permit the use of GM organisms and their products for commercial applications. (ii) To adopt procedures for restriction, production, import, export and application of GM organisms. (iii) To approve for conduct of large scale field trials and release of transgenic crops in the environment. (iv) To curb and take punitive action against agencies if they disturb ecological balance.

Question. List any two molecular diagnostic techniques and write one application of each of them.
Answer :  The two molecular diagnostic technique are as follows : (i) PCR is polymerase chain reaction. It is used to detect HIV infection and mutations in genes in suspected cancer patient. (ii) ELISA is Enzyme- Linked Immunosorbent Assay. It is used to detect infections by pathogens.

Question. Explain the structure of human insulin with the help of a diagram.
Answer : Insulin consists of two short polypeptide chains: chain A and chain B, that are linked together by disulphide bridges. In mammals, including humans, insulin is synthesised as a prohormone which contains an extra stretch called the C peptide. This C peptide is not present in the mature insulin and is removed during maturation into insulin. The given diagram explains the maturation of proinsulin into insulin:

Question. What is a transgenic crop ? Which plant is used to produce blood anticoagulant protein ? What is this protein called?
Answer :  Transgenic crops or genetically modified crop contain and express one or more useful foreign genes or transgenes. Brassica napus is used to produce blood anticoagulant protein. The protein is called hirudin. The protein hirudin is an anticoagulant which is present in leech. Its gene was chemically synthesized and introduced in Brassica napus. The seeds of the latter came to have hirudin which could be extracted and purified.

Long Answer Type Questions

Question. (a) Write short note on the following:
(i) Transgenic tomato
(ii) ANDI
(iii) Transgenic sheep
(b) To which virus is transgenic chicken resistant?
Answer : (a) (i) Flavr Savr is a transgenic variety of tomato. In this variety native tomato gene, which produces enzyme polygalacturonase is inactivated. The non-availability of this enzyme prevents over-ripening because the enzyme is essential for degradation of cell walls. Thus, fruit remains fresh for long time and it also retains flavour, superior taste and higher quantity of total soluble solids. So, it prevents post harvest and over ripening losses, and is preferred over normal native variety. (ii) ANDI – DNA of a fluorescent jelly fish was introduced into an unfertilised egg of a Rhesus monkey in the test tube. The diploid egg underwent cleavage and the early embryo was implanted in a surrogate mother. It has been named ANDI, the acronym of “inserted DNA”. This work would be helpful for curing diseases such as breast cancer, Alzheimer’s disease, diabetes and AIDS. (iii) Tracy, the transgenic ewe was born in Scotland. Transgenic sheep have been produced to achieve better growth and meat production. For example, human genes for blood clotting factor IX and for a1-antitryspin have been transferred in sheep and expressed in mammary tissue. This was achieved by fusing the genes with the mammary tissue-specific promoter of the bovine b-lactoglobulin gene. Human growth hormone gene has also been introduced in sheep in order to promote growth and meat production. However, they also showed several undesirable effects like joint pathology, skeletal defects, gastric ulcers, infertility, etc. (b) Transgenic chicken is resistant to avian leukosis virus (ALV).