What is the fundamental goal of using transgenic animals to study normal physiology and development?

[Biotechnology-and-its-Applications] [class-xii ]

• To mass produce useful biological products like proteins.
• To study how genes are regulated and affect normal bodily functions and development.
• To replace the use of monkeys in vaccine safety testing.
• To increase their sensitivity to toxic substances for faster testing.
Correct Option: B  [ To study how genes are regulated and affect normal bodily functions and development. ]

Remark: Transgenic animals can be specifically designed to allow the study of how genes are regulated, and how they affect the normal functions of the body and its development (Normal physiology and development).

Which human protein used to treat emphysema is targeted for production using transgenic animals?

[Biotechnology-and-its-Applications] [class-xii ]

• Insulin
• Human alpha-lactalbumin
• Alpha-1-antitrypsin
• Growth hormone
Correct Option: C  [ Alpha-1-antitrypsin ]

Remark: Transgenic animals can be created to produce useful biological products, such as the human protein alpha-1-antitrypsin, used to treat emphysema.

Why is the meristem (apical and axillary) of a plant preferred for tissue culture when trying to recover healthy plants from a diseased plant?

[Biotechnology-and-its-Applications] [class-xii ]

• It contains high levels of growth regulators.
• The cells are highly totipotent.
• The meristem is typically free of the virus, even if the rest of the plant is infected.
• It allows for faster regeneration of roots.
Correct Option: C  [ The meristem is typically free of the virus, even if the rest of the plant is infected. ]

Remark: Even if the plant is infected with a virus, the meristem (apical and axillary) is free of virus. Hence, one can remove the meristem and grow it in vitro to obtain virus-free plants.

Genetically modified (GM) plants are beneficial because they have reduced post-harvest losses and increased tolerance to:

[Biotechnology-and-its-Applications] [class-xii ]

• Heavy rainfall
• Abiotic stresses (cold, drought, salt, heat)
• Herbivore feeding
• Soil erosion
Correct Option: B  [ Abiotic stresses (cold, drought, salt, heat) ]

Remark: Genetic modification has made crops more tolerant to abiotic stresses (cold, drought, salt, heat) and helped to reduce post harvest losses.

Insulin is synthesized in mammals as a pro-hormone. What happens to the C peptide during the maturation process?

[Biotechnology-and-its-Applications] [class-xii ]

• It forms the disulphide bridges.
• It is cleaved and removed to form mature insulin.
• It forms the A chain of the insulin molecule.
• It remains attached but becomes inactive.
Correct Option: B  [ It is cleaved and removed to form mature insulin. ]

Remark: Insulin is synthesized as a pro-hormone, which contains an extra stretch called the C peptide. This C peptide is not present in the mature insulin and is removed during maturation into functional insulin.

If the gene for ADA isolated from marrow cells is introduced into cells at early embryonic stages, what is the potential outcome for treating ADA deficiency?

[Biotechnology-and-its-Applications] [class-xii ]

• It would require periodic enzyme injections.
• It could be a permanent cure.
• It would fail due to early embryonic rejection.
• It would lead to excessive ADA production.
Correct Option: B  [ It could be a permanent cure. ]

Remark: If the gene isolated from marrow cells producing ADA is introduced into cells at early embryonic stages, it could be a permanent cure.

The strategy to protect tobacco plants from the nematode Meloidegyne incognitia was based on RNA interference (RNAi), which is a cellular defense mechanism found in:

[Biotechnology-and-its-Applications] [class-xii ]

• Only parasitic nematodes.
• All eukaryotic organisms.
• Only bacteria and fungi.
• Only higher plants and mammals.
Correct Option: B  [ All eukaryotic organisms. ]

Remark: RNAi takes place in all eukaryotic organisms as a method of cellular defense. This involves silencing of a specific mRNA due to a complementary dsRNA molecule.

What is the common ethical concern regarding the introduction of genetically modified organisms (GMOs) into the ecosystem?

[Biotechnology-and-its-Applications] [class-xii ]

• The potential for increased reliance on chemical pesticides.
• The guaranteed spread of the foreign gene to native species.
• The unpredictable results they can have when introduced.
• The rapid depletion of soil nutrients.
Correct Option: C  [ The unpredictable results they can have when introduced. ]

Remark: Genetic modification of organisms can have unpredictable results when such organisms are introduced into the ecosystem, which is a key biological and ethical issue.

Biotechnology essentially deals with industrial scale production of biopharmaceuticals and biologicals using genetically modified microbes, fungi, plants and ________.

[Biotechnology-and-its-Applications] [class-xii ]

• animals
• bacteria
• viruses
• yeasts
Correct Option: A  [ animals ]

Remark: Biotechnology uses genetically modified microbes, fungi, plants, and animals for industrial scale production of biologicals and biopharmaceuticals.

One of the three critical research areas of biotechnology is providing the best catalyst in the form of an improved organism usually a microbe or pure ________.

[Biotechnology-and-its-Applications] [class-xii ]

• hormone
• enzyme
• vitamin
• toxin
Correct Option: B  [ enzyme ]

Remark: The first critical research area is providing the best catalyst, usually a microbe or pure enzyme.