Case Study Questions Class 12 Biology Chapter 12 Biotechnology and it’s Applications
CBSE Class 12 Case Study Questions Biology Biotechnology and it’s Applications. Term 2 Important Case Study Questions for Class 12 Board Exam Students. Here we have arranged some Important Case Base Questions for students who are searching for Paragraph Based Questions Biotechnology and it’s Applications.
At Case Study Questions there will given a Paragraph. In where some Important Questions will made on that respective Case Based Study. There will various types of marks will given 1 marks, 2 marks, 3 marks, 4 marks.
CBSE Case Study Questions Class 12 Biology Biotechnology and it’s Applications
Case Study 1
Let us take a look at the three options that can be thought for increasing food production (i) agro-chemical based agriculture; (ii) organic agriculture; and (iii) genetically engineered crop-based agriculture. The Green Revolution succeeded in tripling the food supply but yet it was not enough to feed the growing human population. Increased yields have partly been due to the use of improved crop varieties, but mainly due to the use of better management practices and use of agrochemicals (fertilisers and pesticides). However, for farmers in the developing world, agrochemicals are often too expensive, and further increases in yield with existing varieties are not possible using conventional breeding. Is there any alternative path that our understanding of genetics can show so that farmers may obtain maximum yield from their fields? Is there a way to minimise the use of fertilisers and chemicals so that their harmful effects on the environment are reduced? Use of genetically modified crops is a possible solution. Plants, bacteria, fungi and animals whose genes have been altered by manipulation are called Genetically Modified Organisms (GMO). GM plants have been useful in many 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 uses, GM has been used to create tailor-made plants to supply alternative resources to industries, in the form of starches, fuels and pharmaceuticals.
Que. 1) Identify correct genetic modification.
(a) Helped to increase post-harvest losses
(b) Made crop less tolerant.
(c) Decreased mineral efficiency.
(d) Early exhaustion of soil fertility is protected.
Que. 2) Genes of ……………………………………………………………………………. Have been altered in the Genetically Modified Organisms.
(a) Animals
(b) Fungi
(c) Bacteria
(d) All of them
Que. 3) ………………………………………………………………………. Revolution has successfully increases food supply.
(a) Orange
(b) Green
(c) Blue
(d) White
Que. 4) Define ‘Genetically Modified Organisms’.
Que. 5) Which two options can increase food production in agricultural biotechnology?
Answer Key
Que. 1)(d) Early exhaustion of soil fertility is protected.
Que. 2) (d) All of them.
Que. 3) (b) Green.
Que. 4) Answer: Genes of bacteria, animals, plants and fungi were altered by manipulation, this is known as ‘Genetically Modified Organisms’.
Que. 5) Answer: Crop based agriculture by genetic engineering and agriculture based on agro-chemical can increase food production in agricultural biotechnology.
Case Study 2
Some of the applications of biotechnology in agriculture that you will study in detail are the production of pest resistant plants, which could decrease the amount of pesticide used. Bt toxin is produced by a bacterium called Bacillus thuringiensis (Bt for short). Bt toxin gene has been cloned from the bacteria and been expressed in plants to provide resistance to insects without the need for insecticides; in effect created a bio-pesticide. Examples are Bt cotton, Bt corn, rice, tomato, potato and soyabean etc. Bt Cotton: Some strains of Bacillus thuringiensis produce proteins that kill certain insects such as lepidopterans (tobacco budworm, armyworm), coleopterans (beetles) and dipterans (flies, mosquitoes). B. thuringiensis forms protein crystals during a particular phase of their growth.
These crystals contain a toxic insecticidal protein. Why does this toxin not kill the Bacillus? Actually, the Bt toxin protein exist as inactive protoxins but once an insect ingest the inactive toxin, it is converted into an active form of toxin due to the alkaline pH of the gut which solubilise the crystals. The activated toxin binds to the surface of midgut epithelial cells and create pores that cause cell swelling and lysis and eventually cause death of the insect.
Que. 1) Bacillus thuringiensis bacterium produces ……………………………………………………………………………………….
(a) Bh toxin
(b) Bb toxin
(c) Bt toxin
(d) Bs toxin
Que. 2) The pest resistant production will ………………………………………………………………………………… the amount of pesticide.
(a) Decrease
(b) Increases
(c) Null
(d) None of these
Que.3) Bt cotton can kill ……………………………………………………………………………..
(a) Mosquito
(b) Armyworm
(c) Beetles
(d) All of them
Que. 4) Give reason:
Bt toxin does not kill the Bacillus.
Que. 5) Name the protein crystal which is formed by Bacillus thuringiensis.
Answer Key
Que. 1)(c) Bt toxin.
Que. 2) (a) Decrease.
Que. 3) (d) All of them.
Que. 4) Answer: Bacillus mainly produces Bt toxin but it exist as inactive protoxins. When the insects ingest this inactive toxin then it becomes an active form of toxin. This active toxin will kill insect. Hence, Bt toxin (Is an inactive form toxin) will not kill bacillus.
Que. 5) Answer: Insecticidal protein is formed by Bacillus thuringiensis.
Case Study 3
Several nematodes parasitise a wide variety of plants and animals including human beings. A nematode Meloidegyne incognitia infects the roots of tobacco plants and causes a great reduction in yield. A novel strategy was adopted to prevent this infestation which was based on the process of RNA interference (RNAi). RNAi takes place in all eukaryotic organisms as a method of cellular defense. This method involves silencing of a specific mRNA due to a complementary dsRNA molecule that binds to and prevents translation of the mRNA (silencing). The source of this complementary RNA could be from an infection by viruses having RNA genomes or mobile genetic elements (transposons) that replicate via an RNA intermediate.
Management of adult-onset diabetes is possible by taking insulin at regular time intervals. Insulin used for diabetes was earlier extracted from pancreas of slaughtered cattle and pigs. Insulin from an animal source, though caused some patients to develop allergy or other types of reactions to the foreign protein. 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 pro-hormone (like a pro-enzyme, the pro-hormone also needs to be processed before it becomes a fully mature and functional hormone) which contains an extra stretch called the C peptide.
Que. 1) Meloidegyne incognitiacauses ……………………………………………………………………………………….. in yield.
(a) Fungal infection
(b) Reduction
(c) Reproduction
(d) Multiplication
Que. 2) In the insulin, Chain A and B were linked by ……………………………………………………………………………………….
(a) Monoxide bridges
(b) Dinitro bridges
(c) Dioxide bridges
(d) Disulphide bridges
Que. 3) Fully mature insulin contains extra stretch is called as ………………………………………………………………………………….
(a) C peptide
(b) D peptide
(c) E peptide
(d) G peptide
Que. 4) Write the full form of RNAi.
Que. 5) Which hormone will help to manage diabetes?
Answer Key
Que. 1)(b) Reduction.
Que. 2) (d) Disulphide bridges.
Que. 3) (a) C peptide.
Que. 4) Answer: Full form of RNAi is RNA interference.
Que. 5) Answer: Insulin is the hormone that manages diabetes.
Case Study 4
If a person is born with a hereditary disease, can a corrective therapy be taken for such a disease? Gene therapy is an attempt to do this. Gene therapy is a collection of methods that allows correction of a gene defect that has been diagnosed in a child/embryo. Here genes are inserted into a person’s cells and tissues to treat a disease. Correction of a genetic defect involves delivery of a normal gene into the individual or embryo to take over the function of and compensate for the non-functional gene. The first clinical gene therapy was given in 1990 to a 4-year old girl with adenosine deaminase (ADA) deficiency. This enzyme is crucial for the immune system to function. The disorder is caused due to the deletion of the gene for adenosine deaminase. In some children ADA deficiency can be cured by bone marrow transplantation; in others it can be treated by enzyme replacement therapy, in which functional ADA is given to the patient by injection. But the problem with both of these approaches that they are not completely curative. As a first step towards gene therapy, lymphocytes from the blood of the patient are grown in a culture outside the body.
A functional ADA cDNA (using a retroviral vector) is then introduced into these lymphocytes, which are subsequently returned to the patient. However, as these cells are not immortal, the patient requires periodic infusion of such genetically engineered lymphocytes. However, if the gene isolate from marrow cells producing ADA is introduced into cells at early embryonic stages, it could be a permanent cure.
Que. 1) In which year, first clinical gene therapy was given?
(a) In 1990
(b) In 1902
(c) In 1940
(d) In 2010
Que. 2) In the Gene therapy, genes are inserted into ……………………………………………………………………………………….. of the person.
(a) Cell
(b) Tissue
(c) Both (a) and (b)
(d) None of these
Que. 3) The ADA deficiency causes due to deletion of ……………………………………………………………………………………….
(a) Therapy
(b) Gene
(c) Retrovirus
(d) Mitochondria
Que. 4) if a person is having hereditary disease since birth and the person want to fix gene defect. Then, which method would you prefer to use?
Que. 5) How can you cure ADA deficiency in the children?
Answer Key
Que. 1)(a) In 1990.
Que. 2) (c) Both (a) and (b).
Que. 3) (b) Gene.
Que. 4) Answer: I would prefer to use Gene therapy method to cure hereditary disease of the person because this method helps to fix gene defect.
Que. 5) Answer: Bone marrow transplantation is the way to cure ADA deficiency in the children.
Case Study 5
You know that for effective treatment of a disease, early diagnosis and understanding its pathophysiology is very important. Using conventional methods of diagnosis (serum and urine analysis, etc.) early detection is not possible. Recombinant DNA technology, Polymerase Chain Reaction (PCR) and Enzyme Linked Immuno-sorbent Assay (ELISA) are some of the techniques that serve the purpose of early diagnosis. Presence of a pathogen (bacteria, viruses, etc.) is normally suspected only when the pathogen has produced a disease symptom. By this time the concentration of pathogen is already very high in the body. However, very low concentration of a bacteria or virus (at a time when the symptoms of the disease are not yet visible) can be detected by amplification of their nucleic acid by PCR. Can you explain how PCR can detect very low amounts of DNA? PCR is now routinely used to detect HIV in suspected AIDS patients. It is being used to detect mutations in genes in suspected cancer patients too. It is a powerful techqnique to identify many other genetic disorders.
A single stranded DNA or RNA, tagged with a radioactive molecule (probe) is allowed to hybridise to its complementary DNA in a clone of cells followed by detection using autoradiography. The clone having the mutated gene will hence not appear on the photographic film, because the probe will not have complementarity with the mutated gene. ELISA is based on the principle of antigen-antibody interaction. Infection by pathogen can be detected by the presence of antigens (proteins, glycoproteins, etc.) or by detecting the antibodies synthesised against the pathogen.
Que. 1) On the principle of antigen-antibody interaction, …………………………………………………………………………………….. is based.
(a) ENISA
(b) ELISA
(c) ECISA
(d) EPISA
Que. 2)……………………………………………………………………… are present in the clones which does not appear on photographic film.
(a) Gene ligase
(b) Polymerase
(c) Non-mutated gene
(d) Mutated gene.
Que. 3) Which of the following technique is continuously used to detect HIV in the AIDs patients?
(a) ADA
(b) BOD
(c) PCR
(d) GMO
Que. 4) What is the full form of ELISA?
Que. 5) When you can suspect presence of pathogen in a person?
Answer Key
Que. 1)(b) ELISA.
Que. 2) (d) Mutated gene.
Que. 3) (c) PCR
Que. 4) Answer: the full form of ELISA is Enzyme Linked Immuno-sorbent Assay.
Que. 5) Answer: When the person will show some symptoms of disease which are produced by bacteria and viruses, then only we can suspect presence of pathogen in a person.
Case Study 6
Animals that have had their DNA manipulated to possess and express an extra (foreign) gene are known as transgenic animals. Transgenic rats, rabbits, pigs, sheep, cows and fish have been produced, although over 95 per cent of all existing transgenic animals are mice. Why are these animals being produced? How can man benefit from such modifications? Let us try and explore some of the common reasons: (i) Normal physiology and development: Transgenic animals can bespecifically designed to allow the study of how genes are regulated, and how they affect the normal functions of the body and its development, e.g., study of complex factors involved in growth such as insulin-like growth factor. By introducing genes from other species that alter the formation of this factor and studying the biological effects that result, information is obtained about the biological role of the factor in the body. (ii) Study of disease: Many transgenic animals are designed to increase our understanding of how genes contribute to the development of disease. These are specially made to serve as models for human diseases so that investigation of new treatments for diseases is made possible. Today transgenic models exist for many human diseases such as cancer, cystic fibrosis, rheumatoid arthritis and Alzheimer’s. (iii) Biological products: Medicines required to treat certain human diseases can contain biological products, but such products are often expensive to make. Transgenic animals that produce useful biological products can be created by the introduction of the portion of DNA (or genes) which codes for a particular product such as human protein (α-1-antitrypsin) used to treat emphysema. Similar attempts are being made for treatment of phenylketonuria (PKU) and cystic fibrosis. In 1997, the first transgenic cow, Rosie, produced human protein-enriched milk (2.4 grams per litre).
The milk contained the human alpha-lactalbumin and was nutritionally a more balanced product for human babies than natural cow-milk. (iv) Vaccine safety: Transgenic mice are being developed for use in testing the safety of vaccines before they are used on humans. Transgenic mice are being used to test the safety of the polio vaccine. If successful and found to be reliable, they could replace the use of monkeys to test the safety of batches of the vaccine. (v) Chemical safety testing: This is known as toxicity/safety testing. The procedure is the same as that used for testing toxicity of drugs. Transgenic animals are made that carry genes which make them more sensitive to toxic substances than non-transgenic animals. They are then exposed to the toxic substances and the effects studied. Toxicity testing in such animals will allow us to obtain results in less time.
Que. 1) For the vaccine testing, transgenic ……………………………………………………………….are being developed.
(a) Snake
(b) Birds
(c) Mice
(d) Insects
Que. 2) Which of the following is treated by α-1-antitrypsin (human protein).
(a) Filariasis
(b) Emphysema
(c) Malaria
(d) Ascariasis
Que. 3) Transgenic animals are …………………………………………………………………………………….. sensitive when compared to other non-transgenic animals.
(a) More
(b) Less
(c) Moderately
(d) None of these
Que. 4) What is meant by transgenic animals?
Que. 5) Why transgenic animals are important in disease study?
Answer Key
Que. 1)(c) Mice.
Que. 2) (b) Emphysema.
Que. 3) (a) More.
Que. 4) Answer: In the animals, the DNA which is manipulated to express an extra gene or foreign gene is known as transgenic animals.
Que. 5) Answer: Transgenic animals helps to investigate new treatment for diseases by serving models. Hence, transgenic animals are important in disease study.