Biotechnology and its Application (Short Questions and Answers)

Biotechnology and its Application

Short Questions and Answers

One mark questions with answers

1. Biopiracy is related to which of the following

(a) traditional knowledge

(b) biomolecules and regarding bioresources

(c) bioresources

(d) all of the above

Answer: (d) all of the above

2. Crystals of Bt toxin produced by some bacteria do not kill the bacteria themselves because

(a) bacteria are resistant to the toxin

(b) toxin is immature

(c) toxin is inactive bacteria

(d) bacteria enclose the toxin in special sac

Answer: (c) toxin is inactive bacteria

 3. It is now possible to breed plants and animals with desired characters through

(a) genetic engineering

(b) chromosome engineering

(c) Ikebana technique

(d) bonsai technique

Answer: (a) genetic engineering

 4. A transgene expression can achieve which of the following

(a) prevent expression of a native gene

(b) modify an existing biosynthetic pathway

(c) produce a protein that itself produces the phenotype of interest

(d) All the above

Answer: (d) All the above

 5. The first transgenic crop was

(a) cotton

(b) flax

(c) pea

(d) tobacco

Answer: (d) tobacco

 6. Addition of foreign gene into crop is

(a) genetic engineering

(b) biotechnology

(c) tissue culture

(d) immunization

Answer: (a) genetic engineering

 7. Transgenic bacteria are being used for producing

(a) epinephrine

(b) human insulin

(c) thyroxine

(d) cortisol

Answer: (b) human insulin

8. Transgenic Golden rice is enriched with high

(a) lysine

(b) methionine

(c) glutein

(d) vitamin A

Answer: (d) vitamin A

 9. Bt toxin is

(a) intracellular lipid

(b) intracellular crystalline protein

(c) extracellular crystalline protein

(d) lipid

Answer: (b) intracellular crystalline protein

 10.  A transgenic crop has gene for

(a) synthesis of new proteins

(b) resistance to antibiotics

(c) formation of enzymes for antibiotics

(d) all of the above

Answer: (d) all of the above

 11. Strains of Bacillus thuringiensis are used in producing

(a) bioinsecticidal plants

(b) biomineralization

(c) bio metallurgical techniques

(d) biofertilizers

Answer: (a) bioinsecticidal plants

 12. Reagent used in ELISA test is

(a) endonuclease

(b) polymerase

(c) ligase

(d) peroxidase

Answer: (d) peroxidase

Two marks questions with answers

1. Define transgenic organism.

Answer: Transgenic organism are organisms which have been modified genetically through introduction of genes of another organism artificially by the technique of genetic engineering instead of conventional hybridization.

 2. What is gene therapy?

Answer: It is a therapeutic treatment of defective heredity the introduction of healthy and functional genes which also silence the defective genes of an individual. Ideally, gene therapy should be applied to zygotes so that the progeny of defective individuals also get rid of the defect. It is generally applied to somatic cells where the defect occurs.

3. With an example, explain how biotechnology has been applied in each of the following:

(i) in curing diabetes mellitus

(ii) in raising pest resistant plants

(iii) in producing more nutritionally balanced milk

Answer: Diabetes mellitus- By producing insulin or humalin from transgenic Escherichia coli.

Pest resistant plants- By m RNA silencing through the technique of RNA interference which produces both sense and antisense RNAs

Transgenic cattle- Cattle having genes for milk proteins, growth hormones and casein given high yield of nutritionally balanced milk with high protein content.

4. What is the cause of adenosine deaminase deficiency in a person?

Answer: The cause is defective ADA gene, which causes nonsynthesis of adenosine deaminase. There is defective purine metabolism and functioning of T-lymphocytes.

Replacement of defective T-lymphocytes with genetically engineered lymphocytes provides immunity but this immunity is temporary upto the life span of the lymphocytes. All new lymphocytes formed will be defective.

Three marks questions with answers

1. What are cry proteins? Name an organism that produces them. How man has exploited proteins to his benefit?

Answer: Cry proteins are a group of toxic proteins which are highly poisonous to different types of insects, example, tobacco bud worm, army worm, beetles, flies and mosquitoes.

The organism producing Cry proteins is Bacillus thuringiensis. The genes controlling their formation were called cry genes. The bacterium produces the protein as endotoxin in protoxin crystalline state.

Two cry genes have been incorporated in cotton (Bt cotton) while one has been introduced in corn. As a result Bt cotton has become resistant to boll worms while Bt corn has developed resistance to corn borer.

2. What are the advantages of producing genetically modified crops?

Answer: (1) Higher yield- Crop plants can be made to grow fast and produce very high yield through genetic modification, example, Super wheat.

(2) Nutritional value- Vitamin A rich Rice and protein rich potato have been developed through genetic engineering.

(3) Stresses- Genetically engineered plants can tolerate drought, frost, salinity, heavy metal toxicity.

(4) Pre harvest losses- Deterioration of harvested product is prevented by inactivation of gene controlling over ripening.

(5) Disease resistance- Resistance to viral disease has been introduced in tobacco, potato, tomato and rice. Cry gene from Bacillus thuringiensis has been introduced in Bt cotton and Bt corn. Nematode infection has been overcome in some plants through RNA interference.

(6) Mineral utilization- Crop plants have been modified to absorb efficiently and utilise minerals.

(7) Pharmaceuticals- Transgenic plants can produce pharmaceuticals like insulin, interferon, blood clotting factors, hormones, etc.

(8) Commercial products- Plants have been modified genetically to yield higher amount of starch, biodiesel and other commercial products.

3. List the disadvantages of production of genetically modified crops.

Answer: (1) Genetic pollution- Transgenes can be transferred from one plant to another plant, microbes and even animals. It shall disturb the genetic setup of organism and cause ecological disbalance.

(2) Superweeds- Weedicides genes are being introduced into crop plants. Any of these crop plants can itself become a super weed.

(3) Super insecticide- Cry gene being introduced in crop plants can pass into wild vegetation. Insects feeding on pollen and other parts will be killed resulting in the destruction of pollinators and disseminators.

(4) Damage to environment- Harvesting leaves a lot of plant residue in the farm land that would damage the biotic environment.

(5) Allergies: The products of transgenes are foreign to human body and animals feeding on tansgenics. This may cause allergy and toxicity.

(6) Antibiotic resistance: Antibiotic resistance gene present in transgenic food can be picked up by bacteria present in human gut and transfer the same to pathogens.

4. What are transgenic bacteria? Ilustrate using any one example.

Answer: Transgenic bacteria are microbes carrying clones of foreign genes. Transgenic bacteria are being employed for a variety of functions.

(1) Biochemical factories- Microbes are used for producing important biochemicals. It is an old use of microbes. Traditionally microbes have been synthesizing alcohol, enzymes, steroids, organic acids and antibiotics. Transgenic bacteria have added a number of biochemicals to this list, example, human insulin, growth hormone, tissue plasminogen factor, erythroprotein, fertility hormone, lung surfactant protein, blood clotting factors, interferons, interleukin etc. Some genetically modified bacteria has been made to augment traditional functions, example, Pseudomonas putida for alcoholic fermentation.

(2) Environmental protection- Microbes have been genetically changed to help in cleaning the polluted environment,example, Pseudomonas putida for cleaning oil spills, Pseudomonas for removing heavy metal pollutants, Acetobacter aerogens for decomposition of DDT and Flavobacterium for decomposition of 2,4-D.