Biotechnology And Its Applications Class 12th Biology CBSE Solution

Class 12^th Biology CBSE Solution

Exercises

1. Crystals of Bt toxin produced by some bacteria do not kill the bacteria themselves because…
2. What are transgenic bacteria? Illustrate using any one example.
3. Compare and contrast the advantages and disadvantages of production of genetically…
4. What are Cry proteins? Name an organism that producse it. How has man exploited this…
5. What is gene therapy? Illustrate using the example of adenosine deaminase (ADA)…
6. Diagrammatically represent the experimental steps in cloning and expressing a human gene…
7. Can you suggest a method to remove oil (hydrocarbon) from seeds based on your…
8. Find out from internet what is golden rice.
9. Does our blood have proteases and nucleases?
10. Consult internet and find out how to make orally active protein pharmaceutical. What is…

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Exercises

Question 1.

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;

D. bacteria encloses toxin in a special sac.

Answer:

C. toxin is inactive;

Bacillus thuringiensis is the bacteria which produces Bt toxins and it is inactive until pest attacks the plant and when it does the toxin get into active state and affects the insects or pests.

Question 2.

What are transgenic bacteria? Illustrate using any one example.

Answer:

transgenic bacteria are found in animals like rat, rabbit, pig, sheep, etc they manipulate their DNA and acts as extra gene or foreign gene. E.g. vaccine safety- polio vaccines are being checked on mice before humans and it was successful and reliable.

Question 3.

Compare and contrast the advantages and disadvantages of production of genetically modified crops.

Answer:

Advantages

• It improves production and raise farmer’s income.

• It reduces the use of insecticides and pesticide sand leads to betterment of foods.

• It can feed a rapidly increasing population because it shows dramatically increased yields.

• Nutritional content was be improved e.g. GMO crops produced rice that was good in vitamin A levels that has reduced global vitamin deficiencies level.

Disadvantages

• GMO crops may cause antibiotics resistance because it have some traces of antibiotics which may cause illness to be difficult to cure.

• Farmers growing genetically modified crops food have legal liability.

• Gene migration can be done with weeds can be worst for future generation crops.

• Honey bees may get affected to these toxin and it may affect apiculture of the region.

Question 4.

What are Cry proteins? Name an organism that producse it. How has man exploited this protein to his benefit?

Answer:

cry proteins is the toxins that is coded as cry gene. It is produced by Bacillus thuringlensis. It is present in GMO crops and acts as insecticides and pesticides.

Question 5.

What is gene therapy? Illustrate using the example of adenosine deaminase (ADA) deficiency.

Answer:

Gene therapy is the collection of methods that allows correction of gene defect that is diagnosed in a child or embryo. Adenosine deaminase gene is deleted from this gene disorder and it can be cured marrow transplantation or by enzyme replacement therapy but since cells are not immortal so this not complete curative. Lymphocytes of the patient are grown in a culture outside the body. Genetically engineered lymphocytes need to be periodically infused but if gene isolated from marrow cells is been changed to producing ADA cells at early embryonic stage it could be permanently cured.

Question 6.

Diagrammatically represent the experimental steps in cloning and expressing a human gene (say the gene for growth hormone) into a bacterium like E. coli?

Answer:

• DNA cloning is the method of producing multiple identical copies of specific DNA template.

• It involves the use of a vector to carry the specific, foreign DNA fragment into the host cell.

• The mechanism of cloning and transfer of gene for growth hormone into E.coli is depicted below.

Question 7.

Can you suggest a method to remove oil (hydrocarbon) from seeds based on your understanding of rDNA technology and chemistry of oil?

Answer:

Recombinant DNA technology is the method used to remove oil from seeds from this method specified gene is been removed so that seeds don’t produce oil.

Question 8.

Find out from internet what is golden rice.

Answer:

golden rice is GMO plant which contains a precursor of vitamin A called as beta carotene which formed from genetic engineering. Beta carotene protein is naturally produces in the process of photosynthesis but absent in the endosperms of the seed.

Question 9.

Does our blood have proteases and nucleases?

Answer:

No, human blood does not contain proteases and nucleases, our blood serum contains inhibitors of proteases reaction which protect proteins from breaking down of the enzyme.

Question 10.

Consult internet and find out how to make orally active protein pharmaceutical. What is the major problem to be encountered?

Answer:

Proteins are digestible in our stomach due to HCL acid releases in or stomach and there is a film inside our stomach which protect our stomach wall proteins from degradation. Digestive enzymes like amylase are used for digestion of protein and may pharmaceutical protein will also get digest before healing of body.