2nd Year NotesBiology class 12th

2nd Year Biology Chapter 23 Biotechnology

2nd Year Biology Chapter 23 Biotechnology Question and Answer

Short and Simple Question And Answer

Q 1. What is the use of genetically engineered bacteria?

Ans. Genetically engineered bacteria are used to clean up environmental pollutants, increase soil fertility, and control insect pests.

Q 2. What are restriction enzymes?

Ans. Restriction enzymes are natural bacterial enzymes used for protection against viruses. They cut DNA at specific sequences.

Q 3. Why are transgenic animals cloned?

Ans. Transgenic animals are cloned to produce a large quantity of a specific product.

Q 4. What is Taq polymerase?

Ans. Taq polymerase is a DNA polymerase extracted from the bacterium Thermus aquaticus, used in DNA amplification because it is thermostable.

Q 5. How are transgenic animals developed?

Ans. Transgenic animals are developed by inserting foreign genes into eggs through techniques like microinjection or vortex mixing.

Q 6. From which animal is antithrombin III produced?

Ans. Antithrombin III is produced from a herd of goats.

Q 7. How many methods are used for gene therapy, and what are they?

Ans. Two main methods are used for gene therapy: ex-vivo and in-vivo.

Q 8. How are transgenic animals that secrete a product often cloned?

Ans. Transgenic animals that secrete a product are often cloned by injecting enucleated eggs with 2n nuclei of adult cells.

Q 9. What is Dolly?

Ans. Dolly was a cloned sheep produced in 1997 at the Roslin Institute in Scotland.

Q 10. When is recombinant DNA technology used, and when is PCR used?

Ans. Recombinant DNA technology is used when a large quantity of a gene is required, while PCR is used to create copies of DNA within a laboratory test tube.

Q 11. How can genes be isolated from chromosomes?

Ans. Genes can be isolated from chromosomes by cutting the chromosomes at specific sites using restriction endonucleases.

Q 12. What is complementary DNA?

Ans. Complementary DNA (cDNA) is synthesized in the laboratory from messenger RNA using reverse transcriptase.

Q 13. What are palindromic sequences?

Ans. Palindromic sequences are specific sequences of four to six nucleotides arranged symmetrically in reverse order that are recognized by restriction enzymes.

Q 14. What are sticky ends?

Ans. Sticky ends are the single-stranded, complementary ends of DNA molecules that can bind through complementary base pairing.

Q 15. What is a vector?

Ans. A vector is a means by which recombinant DNA is introduced into a host cell. Plasmids are a common type of vector.

Q 16. What are plasmids? Ans. Plasmids are natural, circular DNA molecules found in bacteria that can carry genes for antibiotic resistance and other functions.

Q 17. What is the role of DNA ligase?

Ans. DNA ligase is an enzyme that seals the foreign piece of DNA into the vector after cutting and joining DNA fragments.

Q 18. What is recombinant DNA or chimeric DNA?

Ans. Recombinant DNA, also known as chimeric DNA, is formed by joining two different pieces of DNA.

Q 19. What is a clone?

Ans. A clone can refer to a large number of identical DNA molecules, cells, or organisms that are all genetically the same.

Q 20. What is a genome and a genomic library?

Ans. A genome is the full set of genes of an individual, while a genomic library is a collection of bacterial or bacteriophage clones, each containing a specific DNA segment from the source cell.

Q 21. What is a probe?

Ans. A probe is a single-stranded nucleotide sequence used to hybridize with a specific piece of DNA.

Q 22. What is the polymerase chain reaction or PCR?

Ans. PCR is a technique used to rapidly create millions of copies of a specific gene or DNA fragment in a test tube.

Q 23. Why is PCR called a chain reaction?

Ans. PCR is named after DNA polymerase and is considered a chain reaction because DNA replication occurs repeatedly, resulting in millions of copies of the desired DNA.

Q 24. What is DNA fingerprinting?

Ans. DNA fingerprinting is a method that compares DNA fragments for identification.

Q 25. What is gel electrophoresis?

Ans. Gel electrophoresis is a technique used to separate DNA fragments based on their lengths, producing distinctive banding patterns.

Q 26. What is gene sequencing?

Ans. Gene sequencing involves determining the order of nucleotides in a DNA fragment.

Q 27. What are various methods of gene or DNA sequencing?

Ans. There are two main methods: Sanger’s method and Maxam-Gilbert method.

Q 28. What is Sanger’s method?

Ans. Sanger’s method uses dideoxy ribonucleoside triphosphates to terminate DNA synthesis at different sites.

Q 29. What is Maxam-Gilbert method?

Ans. Maxam-Gilbert method chemically cuts DNA into pieces of different sizes.

Q 30. What is the use of the dideoxy method?

Ans. The dideoxy method is used to separate DNA pieces of different sizes on a gel.

Q 31. Name different organisms and organelles whose genomes have been sequenced?

Ans. Genomes of various organisms and organelles, including plant chloroplasts, animal mitochondria, bacteria, yeasts, nematode worms, Drosophila, Arabidopsis, mice, and humans, have been sequenced.

Q 32. What is the primary goal of the Human Genome Project?

Ans. The primary goal of the Human Genome Project is to map human chromosomes, sequence genes along each chromosome, and identify the base pairs in DNA.

Q 33. What are biotechnology products?

Ans. Biotechnology products are products produced by genetically engineered organisms.

Q 34. What are transgenic organisms?

Ans. Transgenic organisms are organisms that have had foreign genes inserted into them.

Q 35. What are bioreactors?

Ans. Bioreactors are large vessels where bacteria reproduce in recombinant DNA technology.

Q 36. Name some biotechnology products produced by bacteria?

Ans. Biotechnology products produced by bacteria include insulin, human growth hormone, tissue plasminogen activator, hemophilia factor VIII, and hepatitis.

Q 37. What are biofilters?

Ans. Biofilters are transgenic organisms used to prevent the release of airborne chemical pollutants into the air, such as bacteria used in industry.

Q 38. What are protoplasts?

Ans. Protoplasts are plant cells with their cell walls removed.

Q 39. Give two advantages of transgenic plants?

Ans. 1) Resistance to pests and herbicides.

  1. Improved dietary contents.

Q 40. Give two advantages of transgenic animals?

Ans. 1) Bovine growth hormone.

  1. Production of larger animals.

Q 41. Define gene therapy?

Ans. Gene therapy is the insertion of genetic material into human cells to treat a disorder.

Q 42. What is ex-vivo gene therapy?

Ans. In ex-vivo gene therapy, normal genes are introduced to patient cells outside the body before returning them to the patient.

Q 43. What is the method of ex-vivo gene therapy?

Ans. Bone marrow stem cells are extracted, infected with a retrovirus carrying a normal gene, and then returned to the patient.

Q 44. What is in-vivo gene therapy?

Ans. In in-vivo gene therapy, patients are directly given normal genes to treat a disorder.

Q 45. What is familial hypercholesterolemia?

Ans. Familial hypercholesterolemia is a condition where liver cells lack receptors for removing cholesterol from the blood, leading to high blood cholesterol levels and increased risk of heart attacks at a young age.

Q 46. What is Cystic fibrosis?

Ans. Cystic fibrosis is a genetic condition where patients lack a gene responsible for chloride ion transport, leading to respiratory tract infections and often fatal outcomes.

Q 47. How has gene therapy been used for cancer treatment?

Ans. In clinical trials, genes are given to cancer patients to make healthy cells more tolerant of chemotherapy or make tumors more vulnerable to it.

Q 48. How has gene therapy been used for coronary artery angioplasty?

Ans. A plasmid with a gene for vascular endothelial growth factor is coated on a balloon catheter to promote blood vessel growth and bypass obstructed areas.

Q 49. What is tissue culture?

Ans. Tissue culture involves growing tissues in an artificial liquid culture medium.

Q 50. Why are plant cells called totipotent?

Ans. Plant cells are totipotent because each cell has the full genetic potential of the organism, enabling a single cell to develop into a complete plant.

Q 51. What is Micro-propagation?

Ans. Micro-propagation is a commercial method for producing thousands or millions of genetically identical seedlings in a limited space.

Q 52. What is Meristem culture?

Ans. Meristem culture is a technique to generate genetically identical shoots and adult plants from a single shoot tip by controlling auxins and cytokinins.

Q 53. What are clonal plants?

Ans. Clonal plants are adult plants that develop from shoots produced by meristem culture, and they are genetically identical, sharing the same traits.

Q 54. What are somaclonal variations?

Ans. Somaclonal variations are slight genetic variations in plants generated from somatic embryos during the production process.

Q 55. What is Anther culture technique?

Ans. Anther culture technique involves culturing mature anthers in a medium with vitamins and growth regulators.

Q 56. What is cell suspension culture technique?

Ans. In the cell suspension culture technique, rapidly growing cultures are broken into single cells or small clumps to produce chemicals similar to the entire plant.

Q 57. What is hybridization and its use?

Ans. Hybridization is the crossing of different plant varieties or species to produce plants with desirable traits.

Q 58. What are luciferase and luciferin?

Ans. Luciferase is a firefly enzyme, and luciferin is its substrate used in experiments to make genetically altered tobacco plants glow.

Q 59. What is Agrobacterium?

Ans. Agrobacterium is a bacterium into which foreign DNA is inserted. It normally infects plant cells and is used in genetic engineering.

Q 60. What is a particle gun?

Ans. A particle gun is a device that bombards plant callus with DNA-coated microscopic metal particles, leading to genetically altered somatic embryos and adult plants.

Q 61. Name some plants made resistant to insect predation and herbicides?

Ans. Cotton, corn, potato, and soybean plants are some examples.

Q 62. What is Arabidopsis?

Ans. Arabidopsis is a salt-tolerant plant developed by genetic engineers.

Q 63. Why are Japanese scientists introducing the C4 photosynthetic cycle into rice?

Ans. Japanese scientists aim to make rice more resistant to hot, dry weather because C4 plants perform well in such conditions.

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