CBSE Class 12 Biology
Revision Notes
CHAPTER- 12
BIOTECHNOLOGY AND ITS APPLICATIONS
Biotechnology deals with industrial scale production of biopharmaceuticals and biological using
genetically modified microbes, fungi, plants and animals. It application includes therapeutics,
diagnostics, genetically modified crops for agriculture, processed food, bioremediation, waste
treatment and energy production. The main three critical research areas of biotechnology
includes-
I. Providing the best catalyst in the form of improved organism usually a microbes or pure
enzyme.
II. Creating optimal conditions through engineering for a catalyst to act.
III. Downstream processing technologies to purify the protein or organic compounds.
Biotechnological Applications in Agriculture- food production can be increased by
a) Agro-chemical based agriculture
b) Organic agriculture
c) Genetically engineered crop-based agriculture.
3Green revolution successfully increased the food production many folds by using better
management practices and use of agrochemicals, fertilizers and pesticides. Further increase in
production is not possible by using these methods. To overcome this genetically modified crop
is used.
3Plants, bacteria, fungi and animals whose genes have been altered by manipulation are called
Genetically Modified Organisms (GMO). GM plants have many applications-
3Made crops more tolerant to abiotic stresses.
3Reduced reliance on chemical pesticides.
3Helped to reduce post harvest losses.
3Increased efficiency of mineral usage by plants.
, 3Enhanced nutritional value of food, eg., Vitamin ‘A’ enriched rice.
Application of Biotechnology in production of pest resistant plants-
Pest resistant plants decrease the amount of pesticides used. Bt toxin is produced by a
bacterium called Bacillus thuringiensis.Bt toxin gene has been cloned from the bacteria and
been expressed in plants to provide resistance to insects without the need for insecticides; in
effect created a bio-pesticide. Examples are Bt cotton, Bt corn, rice, tomato, potato and
soyabean etc.
Bt cotton- Bacterium Bacillus thuringiensis produce proteins that kill certain insects like
lepidopterens, colepterans (beetels) and dipterans (flies, mosquitoes).
•B. thuringiensisproduce crystals that contain a toxic insecticidal protein. This toxic protein
present in bacterium as inactive protoxins but as soon as insect ingest the inactive form due to
alkaline pH of gut, it converted into an active form of toxin and bind to surface of midgut
epithelial cells and create pores that cause cell swelling and lysis and eventually death of insect.
•The gene from B. thuringiensishas been incorporated into several crop plants like cotton, maize,
rice etc. The toxin is coded by a gene named cry. The protein coded by the genes crylAb and
cryIIAb control the cotton bollworms, cryIAb controls corn borer.
Pest Resistant Plants
Nematodes like Meloidegyne incognitia infects the roots of tobacco plants and causes
reduction in yield. The infestation of these nematodes can be prevented by the process of RNA
interference (RNAi). RNAi is present in all eukaryotic organisms as cellular defence by silencing
of specific mRNA due to complementary dsRNA molecules that bind to and prevent translation
of the mRNA.
•The source of complementary dsRNA may be from an infection by viruses having RNA
genomes or mobile genetic elements that replicate through RNA intermediate.
•Nematode specific genes were introduced into host plant using Agrobacterium vectors. The
parasite could not survive in a transgenic host expressing specific interfering RNA.
Biotechnological Applications in Medicine
The rDNA technological processes have made immense impact in the area
of healthcare by enabling mass production of safe and more effective
therapeutic drugs. At present, about 30 recombinant therapeutics have
been approved for human use the world over. In India, 12 of these are
presently being
Revision Notes
CHAPTER- 12
BIOTECHNOLOGY AND ITS APPLICATIONS
Biotechnology deals with industrial scale production of biopharmaceuticals and biological using
genetically modified microbes, fungi, plants and animals. It application includes therapeutics,
diagnostics, genetically modified crops for agriculture, processed food, bioremediation, waste
treatment and energy production. The main three critical research areas of biotechnology
includes-
I. Providing the best catalyst in the form of improved organism usually a microbes or pure
enzyme.
II. Creating optimal conditions through engineering for a catalyst to act.
III. Downstream processing technologies to purify the protein or organic compounds.
Biotechnological Applications in Agriculture- food production can be increased by
a) Agro-chemical based agriculture
b) Organic agriculture
c) Genetically engineered crop-based agriculture.
3Green revolution successfully increased the food production many folds by using better
management practices and use of agrochemicals, fertilizers and pesticides. Further increase in
production is not possible by using these methods. To overcome this genetically modified crop
is used.
3Plants, bacteria, fungi and animals whose genes have been altered by manipulation are called
Genetically Modified Organisms (GMO). GM plants have many applications-
3Made crops more tolerant to abiotic stresses.
3Reduced reliance on chemical pesticides.
3Helped to reduce post harvest losses.
3Increased efficiency of mineral usage by plants.
, 3Enhanced nutritional value of food, eg., Vitamin ‘A’ enriched rice.
Application of Biotechnology in production of pest resistant plants-
Pest resistant plants decrease the amount of pesticides used. Bt toxin is produced by a
bacterium called Bacillus thuringiensis.Bt toxin gene has been cloned from the bacteria and
been expressed in plants to provide resistance to insects without the need for insecticides; in
effect created a bio-pesticide. Examples are Bt cotton, Bt corn, rice, tomato, potato and
soyabean etc.
Bt cotton- Bacterium Bacillus thuringiensis produce proteins that kill certain insects like
lepidopterens, colepterans (beetels) and dipterans (flies, mosquitoes).
•B. thuringiensisproduce crystals that contain a toxic insecticidal protein. This toxic protein
present in bacterium as inactive protoxins but as soon as insect ingest the inactive form due to
alkaline pH of gut, it converted into an active form of toxin and bind to surface of midgut
epithelial cells and create pores that cause cell swelling and lysis and eventually death of insect.
•The gene from B. thuringiensishas been incorporated into several crop plants like cotton, maize,
rice etc. The toxin is coded by a gene named cry. The protein coded by the genes crylAb and
cryIIAb control the cotton bollworms, cryIAb controls corn borer.
Pest Resistant Plants
Nematodes like Meloidegyne incognitia infects the roots of tobacco plants and causes
reduction in yield. The infestation of these nematodes can be prevented by the process of RNA
interference (RNAi). RNAi is present in all eukaryotic organisms as cellular defence by silencing
of specific mRNA due to complementary dsRNA molecules that bind to and prevent translation
of the mRNA.
•The source of complementary dsRNA may be from an infection by viruses having RNA
genomes or mobile genetic elements that replicate through RNA intermediate.
•Nematode specific genes were introduced into host plant using Agrobacterium vectors. The
parasite could not survive in a transgenic host expressing specific interfering RNA.
Biotechnological Applications in Medicine
The rDNA technological processes have made immense impact in the area
of healthcare by enabling mass production of safe and more effective
therapeutic drugs. At present, about 30 recombinant therapeutics have
been approved for human use the world over. In India, 12 of these are
presently being
