Biotechnology AND ITS Application flash cards

1. 1.What are the three critical research areas of biotechnology?

   (1) Providing the best catalyst as improved organism (usually a microbe or pure enzyme); (2) creating optimal conditions for the catalyst to act; (3) downstream processing to purify the protein/organic compound.

   Hint: Catalyst, conditions, purification.

2. 2.Name the two major techniques that helped modern biotechnology take birth.

   Genetic engineering (recombinant DNA technology, gene cloning, gene transfer) and chemical engineering processes for sterile ambience to grow desired microbes/eukaryotic cells in large quantities.

   Hint: One alters genes, one scales up production.

3. 3.In how many broad fields have biotechnological applications been categorised?

   Three: therapeutics, diagnostics, genetically modified crops for agriculture, processed food, bioremediation, waste treatment and energy production — chiefly grouped as agriculture, medicine and industry.

   Hint: Agriculture, medicine, industry.

4. 4.What are the three options mankind has to increase food production?

   (1) Agro-chemical based agriculture; (2) organic agriculture; (3) genetically engineered crop-based agriculture.

   Hint: Chemicals, organic, GM.

5. 5.Define the Green Revolution.

   The tripling of food supply achieved through use of improved crop varieties, better management practices and use of agrochemicals (fertilisers and pesticides), though yield was still insufficient with growing population.

   Hint: Improved varieties + agrochemicals tripled food.

6. 6.Why were agrochemicals (fertilisers, pesticides) a limitation of the Green Revolution?

   They are expensive (unaffordable to poor farmers) and cause environmental pollution/damage. Further yield rise needs alternative paths.

   Hint: Costly and polluting.

7. 7.What are GMOs?

   Genetically Modified Organisms — plants, bacteria, fungi and animals whose genes have been altered by manipulation.

   Hint: Manipulated genes.

8. 8.List the ways in which genetic modification has made crops more useful.

   (1) Made crops more tolerant to abiotic stresses (cold, drought, salt, heat); (2) reduced reliance on chemical pesticides (pest-resistant crops); (3) reduced post-harvest losses; (4) increased efficiency of mineral usage by plants (preventing early soil exhaustion); (5) enhanced nutritional value of food, e.g. Vitamin A enriched rice.

   Hint: Stress tolerance, less pesticide, less loss, better minerals, better nutrition.

9. 9.QUESTION: A crop plant has been modified to survive high-salinity soil. Which category of usefulness does this represent?

   Tolerance to abiotic (environmental) stresses — cold, drought, salt and heat. This lets crops grow in otherwise unusable land.

   Hint: Salt is a non-living stress.

10. 10.Besides improving crops, give two non-agricultural uses of GM plants/biotechnology.

    (1) To create tailor-made plants supplying alternative resources to industries in the form of starches, fuels and pharmaceuticals; (2) production of biofuels and biofortified/biopharmaceutical products.

    Hint: Industry raw material and pharma.

11. 11.What is Bt in 'Bt cotton', 'Bt corn' etc.?

    Bt is derived from Bacillus thuringiensis, a bacterium that produces proteins (insecticidal Cry proteins) which kill certain insects such as lepidopterans, coleopterans and dipterans.

    Hint: A soil bacterium's toxin.

12. 12.What is the scientific name of the bacterium that provides the Bt toxin?

    Bacillus thuringiensis.

    Hint: Its species name gives the two t's in 'Bt'.

13. 13.In what form does Bacillus thuringiensis form the Bt toxin, and why is it not toxic to the bacterium itself?

    During a particular phase of growth the bacteria form protein crystals containing a toxic insecticidal protein. The toxin exists as inactive protoxins (crystals); being inactive, it does not harm the bacterium.

    Hint: Stored as an inactive crystal protoxin.

14. 14.Explain how the Bt toxin becomes active after an insect eats it.

    The inactive protoxin (crystal) is ingested by the insect; in the alkaline pH of the insect gut, the crystal is solubilised and converted into the active form of toxin.

    Hint: Alkaline gut solubilises the crystal.

15. 15.By what mechanism does the activated Bt toxin kill the insect?

    The activated toxin binds to the surface of midgut epithelial cells and creates pores that cause cell swelling and lysis, eventually causing death of the insect.

    Hint: Pores in midgut cells → lysis.

16. 16.What are cry genes, and what do they code for?

    Specific Bt toxin genes (cry genes) isolated from Bacillus thuringiensis and incorporated into crops; they code for the insecticidal Cry proteins (protoxins).

    Hint: Named after 'cry'stal proteins.

17. 17.Which Cry proteins control cotton bollworms and which control corn borer?

    The proteins encoded by genes cryIAc and cryIIAb control the cotton bollworms; the protein of cryIAb controls corn borer.

    Hint: cryIAc & cryIIAb → cotton; cryIAb → corn.

18. 18.QUESTION: Why is Bt cotton harmless to humans and non-target animals but lethal to bollworms?

    The protoxin is activated only in the alkaline gut of susceptible insects; the human/animal gut is acidic and lacks the specific receptors, so the toxin stays inactive and the specific midgut binding does not occur.

    Hint: Activation needs an alkaline gut + specific receptors.

19. 19.What is RNA interference (RNAi)?

    A method of cellular defence in eukaryotes that involves silencing of a specific mRNA due to a complementary double-stranded RNA (dsRNA) molecule that binds to and prevents translation of the mRNA.

    Hint: dsRNA silences a specific mRNA.

20. 20.What is the natural role of RNAi in cells?

    It is a cellular defence occurring in all eukaryotic organisms; the source of complementary RNA may be from infection by viruses (with RNA genomes) or mobile genetic elements (transposons) that replicate via an RNA intermediate.

    Hint: Defence against viruses and transposons.

21. 21.Describe how RNAi was used to develop nematode-resistant tobacco plants.

    A nematode Meloidogyne incognita infects tobacco roots and reduces yield. Using Agrobacterium as a vector, nematode-specific genes were introduced into the host plant to produce sense and anti-sense RNA. These two complementary RNAs formed a dsRNA that initiated RNAi and silenced the specific nematode mRNA. The parasite could not survive in the transgenic host, so the plant was protected.

    Hint: Host makes dsRNA against a nematode gene.

22. 22.Name the nematode that parasitises the roots of tobacco plants (used in the RNAi example).

    Meloidogyne incognita.

    Hint: A root-knot nematode.

23. 23.In the nematode RNAi strategy, what produced the double-stranded RNA in the plant?

    Introduction of nematode-specific genes into the host, using Agrobacterium as vector, produced both sense and anti-sense RNA in the host cells; being complementary, they formed the dsRNA.

    Hint: Sense + anti-sense = dsRNA.

24. 24.What is biofortification?

    Breeding/engineering crops with higher levels of vitamins and minerals, or higher protein and healthier fats, to improve public health — the most practical means to improve nutrition of the majority.

    Hint: Nutrient-enriched crops.

25. 25.List the objectives that biofortified crops aim to improve.

    (1) Protein content and quality; (2) oil content and quality; (3) vitamin content; (4) micronutrient and mineral content.

    Hint: Protein, oil, vitamins, minerals.

26. 26.Give the example of a biofortified maize hybrid and its improvement.

    Maize hybrids released in 2000 had twice the amount of the amino acids lysine and tryptophan compared to existing maize hybrids.

    Hint: Double lysine and tryptophan.

27. 27.Name a biofortified wheat variety and its enhanced nutrient.

    Wheat variety 'Atlas 66', which has a high protein content.

    Hint: An early high-protein wheat.

28. 28.Which biofortified rice variety is rich in iron, and by how much?

    A rice variety developed with over five times more iron than commonly consumed varieties.

    Hint: >5x the iron.

29. 29.Name the vegetables developed by IARI with enriched vitamins and minerals.

    Carrots, spinach and bumpkin rich in vitamin A; bathua, mustard and tomato rich in iron and calcium; and bitter gourd, bathua, mustard and tomato rich in protein — all developed by the Indian Agricultural Research Institute (IARI), New Delhi.

    Hint: IARI, New Delhi vegetables.

30. 30.What are the two chief experimental applications of microbes/bacteria as GMOs alluded to for medicine and food?

    Producing therapeutic proteins/drugs and processed foods; genetically modified microbes are used in bioremediation, waste treatment and energy production too.

    Hint: Drugs, food, environment.

Open the interactive deck for the other 65 cards, with self-grading so the ones you keep missing come back.