Q.1. Match the following columns and select the correct option. (2020)
(a) 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.
(b) The first clinical gene therapy was given in 1990 to a 4-year old girl with adenosine deaminase (ADA) deficiency.
(c) RNAi (RNA interference) is a biological process in which RNA molecules inhibit gene expression or translation, by neutralizing targeted mRNA molecules and takes place in all eukaryotic organisms as a method of cellular defense.
(d) Polymerase chain reaction can be used in detection of HIV infection as it detects the genetic material of HIV i.e. its RNA
Q.2. Which of the following statements is not correct? (2020)
(a) The functional insulin has A and B chains linked together by hydrogen bonds.
(b) Genetically engineered insulin is produced in E-Coli.
(c) In man insulin is synthesised as a proinsulin.
(d) The proinsulin has an extra peptide called C-peptide.
The functional insulin molecule has two chains A and chain B, that are linked together by disulphide bridges and not hydrogen bonds.
Q.3. Bt cotton variety that was developed by the introduction of toxin gene of Bacillus thuringiensis (Bt) is resistant to : (2020)
(a) Plant nematodes
(b) Insect predators
(c) Insect pests
(d) Fungal diseases
B. thuringiensis forms protein crystals during a particular phase of their growth. These crystals contain a toxic insecticidal protein. Bt cotton is an insect-resistant transgenic crop designed to combat the bollworm.
Q.4. What triggers activation of protoxin to active toxin of Bacillus thuringiensis in boll worm? (2019)
(a) Acidic pH of stomach
(b) Body temperature
(c) Moist surface of midgut
(d) Alkaline pH of gut
Some strains of Bacillus thuringiensis produce proteins that kill certain insects such as lepidopterans and dipterans. B. thuringiensis forms protein crystals during a particular phase of their growth. These crystals contain a toxic insecticidal protein which exists 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.
Q.5. Which of the following is true for Golden rice? (2019)
(a) It has yellow grains, because of a gene introduced front a primitive variety of rice,
(b) It is vitamin A enriched, with a gene from daffodil.
(c) It is pest resistant, with a gene from Bacillus thuringiensis.
(d) It is drought tolerant, developed using Agrobacterium vector.
Rice is a staple food in many countries, particularly in Asia, but does not contain vitamin A or its immediate precursors. By inserting two genes from daffodil and one gene from a bacterial species into rice plants, Swiss researchers have produced rice capable of synthesising β-carotene, the precursor of vitamin A. Vitamin A is required by all individuals as it is present in retina of eyes. Deficiency of vitamin A causes night blindness and skin disorders. This rice is called ‘Golden rice’ because of yellow colour of rice grains due to the presence of β-carotene.
Q.6. In RNAi, the genes are silenced using: (2019)
Q.7. Which of the following is commonly used as a vector for introducing a DNA fragment in human lymphocytes? (2018)
(b) Ti plasmid
(c) λ phage
Retroviruses cause cancer in animals including humans. So modified retroviruses are used to transfer desirable genes into animal cells. It is used in gene therapy, in which lymphocytes from blood of patient are taken and grown in culture medium outside the body, a functional gene is introduced by using a retroviral vector into these lymphocytes which are again reintroduced into the patient body.
Q.8. In India, the organisation responsible for assessing the safety of introducing genetically modified organisms for public use is (2018)
(a) Indian Council of Medical Research (ICMR)
(b) Council for Scientific and Industrial Research (CSIR)
(c) Research Committee on Genetic Manipulation (RCGM)
(d) Genetic Engineering Appraisal Committee (GEAC)
Indian government has set up organisation such as GEAC (Genetic Engineering Appraisal Committee) which makes decisions regarding the validity of GM research and safety of introducing GM organisms for public services.
Q.9. A ‘new’ variety of rice was patented by a foreign company, though such varieties have been present in India for a long time, This is related to (2018)
(b) Sharbati Sonora
(c) Lerma Rojo
In 1997, a Texas company got patent rights on Basmati rice through the US Patent and Trademark Office. This allowed the company to sell a ‘new’ variety of Basmati, in the US and abroad. This new variety of Basmati had actually been derived from Indian farmers’ varieties. Indian Basmati was crossed with semi-dwarf varieties and claimed as an invention or a novelty. It caused a brief diplomatic crisis between India and United States will) India threatening to take the matter to WTO (World Trade Organisation) as a violation of TRIPS (Trade Related Aspects of Intellectual Property Rights). Both voluntarily and due to review decisions by United States patent office, Rice Tec lost most of the claims of the patent.
Q.10. Use of bioresources by multinational companies and organisations without authorisation from the concerned country and its people is called (2018)
Some organisations and multinational companies exploit or patent biological resources or bioresources of other nations without proper authorisation from the countries concerned. This is called biopiracy.
Q.11. Which kind of therapy was given in 1990 to a four-year-old girl with adenosine deaminase (ADA) deficiency? (2016)
(a) Gene therapy
(d) Radiation therapy
Gene therapy is a technique of genetic engineering which involves replacement of a faulty/disease causing gene by a normal healthy 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 very important for the immune system to function. The deficiency of this enzyme can lead to severe combined immune deficiency (SCID).
Q.12. The two polypeptides of human insulin are linked together by (2016)
(a) Covalent bond
(b) Disulphide bridges
(c) Hydrogen bonds
(d) Phosphodiester bond
Human insulin is made up of 51 amino acids arranged in two polypeptide chains. Chain A has 21 amino acids and chain B has 30 amino acids. The two polypeptide chains are interconnected by disulphide bridges or S-S-linkages.
Q.13. Which part of the tobacco plant is infected by Meloidogyne incognita? (2016)
Meloidogyne incognita is a nematode which infects the roots of the tobacco plants and causes a great reduction in the yield.
Q.14. The crops engineered for glyphosate are resistant/ tolerant to: (2015)
Today plants having the broad leaves are made resistant to a powerful biodegradable herbicide glyphosate. It is an active ingredient of Round Up ready plant. It disturbs the working of EPSP synthetase enzyme. If it is taken up by crop plants they will die. So, the bioengineers have transferred gene for synthesis of EPSP synthetase enzyme to crop plant.
Q.15. In Bt cotton, the Bt toxin present in plant tissue as pro-toxin is converted into active toxin due to: (2015)
(a) Acidic pH of the insect gut
(b) Action of gut micro-organisms
(c) Presence of conversion factors in insect gut
(d) Alkaline pH of the insect gut
Bt toxin are solubilised in alkaline pH of the insect gut causing death.
Q.16. Which body of the Government of India regulates GM research and safety of introducing GM organisms for public services ? (2015)
(a) Indian Council of Agricultural Research
(b) Genetic Engineering Approval Committee
(c) Research Committee on Genetic Manipulation
(d) Bio-safety committee
Genetic Engineering Approval Committee is the body of Government of India. It regulates GM research and safety of introducing GM organisms for public service in the country.
Q.17. Golden rice is a genetically modified crop plant where the incorporated gene is meant for biosynthesis of : (2015)
(a) Vitamin C
(b) Omega 3
(c) Vitamin A
(d) Vitamin B
Golden rice (Oryza sativa) is a genetically modified crop. It biosynthesizes β - carotene which is the precursor of vitamin-A.
Q.18. Pollen tablets are available in the market for: (2014)
(a) In vitro fertilization
(b) Breeding programmes
(c) Supplementing food
(d) Ex situ conservation
Pollen grains are rich in nutrients therefore used as food supplements. Athletes and race horses use these as tablets to enhance performance.
Q.19. The first human hormone produced by recombinant DNA technology is: (2014)
Mammalian hormones were among the first products prepared in bacteria by r-DNA technology. Human insulin and human growth hormone are earliest examples.