NCERT Textbook: Biotechnology & Its Applications | Biology Class 12 - NEET PDF Download

 Page 1


Biotechnology, as you would have learnt from the
previous chapter, essentially deals with industrial scale
production of biopharmaceuticals and biologicals using
genetically modified microbes, fungi, plants and animals.
The applications of biotechnology include therapeutics,
diagnostics, genetically modified crops for agriculture,
processed food, bioremediation, waste treatment, and
energy production. Three critical research areas of
biotechnology are:
(i) Providing the best catalyst in the form of improved
organism usually a microbe or pure enzyme.
(ii) Creating optimal conditions through engineering for
a catalyst to act, and
(iii) Downstream processing technologies to purify the
protein/organic compound.
Let us now learn how human beings have used
biotechnology to improve the quality of human life,
especially in the field of food production and health.
10.1 BIOTECHNOLOGICAL APPLICATIONS IN
AGRICULTURE
Let us take a look at the three options that can be thought
for increasing food production
(i) agro-chemical based agriculture;
CHAPTER 10
BIOTECHNOLOGY AND ITS
APPLICATIONS
10.1 Biotechnological
Applications in
Agriculture
10.2 Biotechnological
Applications in
Medicine
10.3 Transgenic Animals
10.4 Ethical Issues
2024-25
Page 2


Biotechnology, as you would have learnt from the
previous chapter, essentially deals with industrial scale
production of biopharmaceuticals and biologicals using
genetically modified microbes, fungi, plants and animals.
The applications of biotechnology include therapeutics,
diagnostics, genetically modified crops for agriculture,
processed food, bioremediation, waste treatment, and
energy production. Three critical research areas of
biotechnology are:
(i) Providing the best catalyst in the form of improved
organism usually a microbe or pure enzyme.
(ii) Creating optimal conditions through engineering for
a catalyst to act, and
(iii) Downstream processing technologies to purify the
protein/organic compound.
Let us now learn how human beings have used
biotechnology to improve the quality of human life,
especially in the field of food production and health.
10.1 BIOTECHNOLOGICAL APPLICATIONS IN
AGRICULTURE
Let us take a look at the three options that can be thought
for increasing food production
(i) agro-chemical based agriculture;
CHAPTER 10
BIOTECHNOLOGY AND ITS
APPLICATIONS
10.1 Biotechnological
Applications in
Agriculture
10.2 Biotechnological
Applications in
Medicine
10.3 Transgenic Animals
10.4 Ethical Issues
2024-25
178
BIOLOGY
(ii) organic agriculture; and
(iii) genetically engineered crop-based agriculture.
The Green Revolution succeeded in tripling the food supply but yet
it was not enough to feed the growing human population. Increased yields
have partly been due to the use of improved crop varieties, but mainly
due to the use of better management practices and use of agrochemicals
(fertilisers and pesticides). However, for farmers in the developing world,
agrochemicals are often too expensive, and further increases in yield with
existing varieties are not possible using conventional breeding.
As traditional breeding techniques failed to keep pace with demand and
to provide sufficiently fast and efficient systems for crop improvement,
another technology called tissue culture got developed. What does
tissue culture mean? It was learnt by scientists, during 1950s, that
whole plants could be regenerated from explants, i.e., any part of a
plant taken out and grown in a test tube, under sterile conditions in
special nutrient media. This capacity to generate a whole plant from
any cell/explant is called totipotency. You will learn how to accomplish
this in higher classes. It is important to stress here that the nutrient
medium must provide a carbon source such as sucrose and also
inorganic salts, vitamins, amino acids and growth regulators like auxins,
cytokinins etc. By application of these methods it is possible to achieve
propagation of a large number of plants in very short durations. This
method of producing thousands of plants through tissue culture is
called micro-propagation. Each of these plants will be genetically
identical to the original plant from which they were grown, i.e., they are
somaclones.  Many important food plants like tomato, banana, apple,
etc., have been produced on commercial scale using this method. Try to
visit a tissue culture laboratory with your teacher to better understand
and appreciate the process.
Another important application of the method is the recovery of
healthy plants from diseased plants. 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.
Scientists have succeeded in culturing meristems of banana, sugarcane,
potato, etc.
Scientists have even isolated single cells from plants and after
digesting their cell walls have been able to isolate naked protoplasts
(surrounded by plasma membranes).  Isolated protoplasts from two
different varieties of plants – each having a desirable character – can be
fused to get hybrid protoplasts, which can be further grown to form a
new plant. These hybrids are called somatic hybrids while the process
2024-25
Page 3


Biotechnology, as you would have learnt from the
previous chapter, essentially deals with industrial scale
production of biopharmaceuticals and biologicals using
genetically modified microbes, fungi, plants and animals.
The applications of biotechnology include therapeutics,
diagnostics, genetically modified crops for agriculture,
processed food, bioremediation, waste treatment, and
energy production. Three critical research areas of
biotechnology are:
(i) Providing the best catalyst in the form of improved
organism usually a microbe or pure enzyme.
(ii) Creating optimal conditions through engineering for
a catalyst to act, and
(iii) Downstream processing technologies to purify the
protein/organic compound.
Let us now learn how human beings have used
biotechnology to improve the quality of human life,
especially in the field of food production and health.
10.1 BIOTECHNOLOGICAL APPLICATIONS IN
AGRICULTURE
Let us take a look at the three options that can be thought
for increasing food production
(i) agro-chemical based agriculture;
CHAPTER 10
BIOTECHNOLOGY AND ITS
APPLICATIONS
10.1 Biotechnological
Applications in
Agriculture
10.2 Biotechnological
Applications in
Medicine
10.3 Transgenic Animals
10.4 Ethical Issues
2024-25
178
BIOLOGY
(ii) organic agriculture; and
(iii) genetically engineered crop-based agriculture.
The Green Revolution succeeded in tripling the food supply but yet
it was not enough to feed the growing human population. Increased yields
have partly been due to the use of improved crop varieties, but mainly
due to the use of better management practices and use of agrochemicals
(fertilisers and pesticides). However, for farmers in the developing world,
agrochemicals are often too expensive, and further increases in yield with
existing varieties are not possible using conventional breeding.
As traditional breeding techniques failed to keep pace with demand and
to provide sufficiently fast and efficient systems for crop improvement,
another technology called tissue culture got developed. What does
tissue culture mean? It was learnt by scientists, during 1950s, that
whole plants could be regenerated from explants, i.e., any part of a
plant taken out and grown in a test tube, under sterile conditions in
special nutrient media. This capacity to generate a whole plant from
any cell/explant is called totipotency. You will learn how to accomplish
this in higher classes. It is important to stress here that the nutrient
medium must provide a carbon source such as sucrose and also
inorganic salts, vitamins, amino acids and growth regulators like auxins,
cytokinins etc. By application of these methods it is possible to achieve
propagation of a large number of plants in very short durations. This
method of producing thousands of plants through tissue culture is
called micro-propagation. Each of these plants will be genetically
identical to the original plant from which they were grown, i.e., they are
somaclones.  Many important food plants like tomato, banana, apple,
etc., have been produced on commercial scale using this method. Try to
visit a tissue culture laboratory with your teacher to better understand
and appreciate the process.
Another important application of the method is the recovery of
healthy plants from diseased plants. 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.
Scientists have succeeded in culturing meristems of banana, sugarcane,
potato, etc.
Scientists have even isolated single cells from plants and after
digesting their cell walls have been able to isolate naked protoplasts
(surrounded by plasma membranes).  Isolated protoplasts from two
different varieties of plants – each having a desirable character – can be
fused to get hybrid protoplasts, which can be further grown to form a
new plant. These hybrids are called somatic hybrids while the process
2024-25
179
BIOTECHNOLOGY AND ITS APPLICATIONS
is called somatic hybridisation. Imagine a situation when a protoplast
of tomato is fused with that of potato, and then they are grown – to form
new hybrid plants combining tomato and potato characteristics. Well,
this has been achieved – resulting in formation of pomato; unfortunately
this plant did not have all the desired combination of characteristics for
its commercial utilisation.
Is there any alternative path that our understanding of genetics can
show so that farmers may obtain maximum yield from their fields? Is
there a way to minimise the use of fertilisers and chemicals so that their
harmful effects on the environment are reduced? Use of genetically
modified crops is a possible solution.
Plants, bacteria, fungi and animals whose genes have been altered by
manipulation are called Genetically Modified Organisms (GMO). GM
plants have been useful in many ways. Genetic modification has:
(i) made crops more tolerant to abiotic stresses (cold, drought, salt, heat).
(ii) reduced reliance on chemical pesticides (pest-resistant crops).
(iii) helped to reduce post harvest losses.
(iv) increased efficiency of mineral usage by plants (this prevents early
exhaustion of fertility of soil).
(v) enhanced nutritional value of food, e.g., golden rice, i.e., Vitamin ‘A’
enriched rice.
In addition to these uses, GM has been used to create tailor-made
plants to supply alternative resources to industries, in the form of starches,
fuels and pharmaceuticals.
Some of the applications of biotechnology in agriculture that you will
study in detail are the production of pest resistant plants, which could
decrease the amount of pesticide used. Bt toxin is produced by a
bacterium called Bacillus thuringiensis (Bt for short).  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: Some strains of Bacillus thuringiensis produce proteins that
kill certain insects such as lepidopterans (tobacco budworm, armyworm),
coleopterans (beetles) and dipterans (flies, mosquitoes).  B. thuringiensis
forms protein crystals during a particular phase of their growth. These
crystals contain a toxic insecticidal protein. Why does this toxin not kill
the Bacillus? Actually, the Bt toxin protein exist as inactive protoxins but
once an insect ingest the inactive toxin, it is converted into an active form
of toxin due to the alkaline pH of the gut which solubilise the crystals.
The activated toxin binds to the surface of midgut epithelial cells and
create pores that cause cell swelling and lysis and eventually cause death
of the insect.
2024-25
Page 4


Biotechnology, as you would have learnt from the
previous chapter, essentially deals with industrial scale
production of biopharmaceuticals and biologicals using
genetically modified microbes, fungi, plants and animals.
The applications of biotechnology include therapeutics,
diagnostics, genetically modified crops for agriculture,
processed food, bioremediation, waste treatment, and
energy production. Three critical research areas of
biotechnology are:
(i) Providing the best catalyst in the form of improved
organism usually a microbe or pure enzyme.
(ii) Creating optimal conditions through engineering for
a catalyst to act, and
(iii) Downstream processing technologies to purify the
protein/organic compound.
Let us now learn how human beings have used
biotechnology to improve the quality of human life,
especially in the field of food production and health.
10.1 BIOTECHNOLOGICAL APPLICATIONS IN
AGRICULTURE
Let us take a look at the three options that can be thought
for increasing food production
(i) agro-chemical based agriculture;
CHAPTER 10
BIOTECHNOLOGY AND ITS
APPLICATIONS
10.1 Biotechnological
Applications in
Agriculture
10.2 Biotechnological
Applications in
Medicine
10.3 Transgenic Animals
10.4 Ethical Issues
2024-25
178
BIOLOGY
(ii) organic agriculture; and
(iii) genetically engineered crop-based agriculture.
The Green Revolution succeeded in tripling the food supply but yet
it was not enough to feed the growing human population. Increased yields
have partly been due to the use of improved crop varieties, but mainly
due to the use of better management practices and use of agrochemicals
(fertilisers and pesticides). However, for farmers in the developing world,
agrochemicals are often too expensive, and further increases in yield with
existing varieties are not possible using conventional breeding.
As traditional breeding techniques failed to keep pace with demand and
to provide sufficiently fast and efficient systems for crop improvement,
another technology called tissue culture got developed. What does
tissue culture mean? It was learnt by scientists, during 1950s, that
whole plants could be regenerated from explants, i.e., any part of a
plant taken out and grown in a test tube, under sterile conditions in
special nutrient media. This capacity to generate a whole plant from
any cell/explant is called totipotency. You will learn how to accomplish
this in higher classes. It is important to stress here that the nutrient
medium must provide a carbon source such as sucrose and also
inorganic salts, vitamins, amino acids and growth regulators like auxins,
cytokinins etc. By application of these methods it is possible to achieve
propagation of a large number of plants in very short durations. This
method of producing thousands of plants through tissue culture is
called micro-propagation. Each of these plants will be genetically
identical to the original plant from which they were grown, i.e., they are
somaclones.  Many important food plants like tomato, banana, apple,
etc., have been produced on commercial scale using this method. Try to
visit a tissue culture laboratory with your teacher to better understand
and appreciate the process.
Another important application of the method is the recovery of
healthy plants from diseased plants. 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.
Scientists have succeeded in culturing meristems of banana, sugarcane,
potato, etc.
Scientists have even isolated single cells from plants and after
digesting their cell walls have been able to isolate naked protoplasts
(surrounded by plasma membranes).  Isolated protoplasts from two
different varieties of plants – each having a desirable character – can be
fused to get hybrid protoplasts, which can be further grown to form a
new plant. These hybrids are called somatic hybrids while the process
2024-25
179
BIOTECHNOLOGY AND ITS APPLICATIONS
is called somatic hybridisation. Imagine a situation when a protoplast
of tomato is fused with that of potato, and then they are grown – to form
new hybrid plants combining tomato and potato characteristics. Well,
this has been achieved – resulting in formation of pomato; unfortunately
this plant did not have all the desired combination of characteristics for
its commercial utilisation.
Is there any alternative path that our understanding of genetics can
show so that farmers may obtain maximum yield from their fields? Is
there a way to minimise the use of fertilisers and chemicals so that their
harmful effects on the environment are reduced? Use of genetically
modified crops is a possible solution.
Plants, bacteria, fungi and animals whose genes have been altered by
manipulation are called Genetically Modified Organisms (GMO). GM
plants have been useful in many ways. Genetic modification has:
(i) made crops more tolerant to abiotic stresses (cold, drought, salt, heat).
(ii) reduced reliance on chemical pesticides (pest-resistant crops).
(iii) helped to reduce post harvest losses.
(iv) increased efficiency of mineral usage by plants (this prevents early
exhaustion of fertility of soil).
(v) enhanced nutritional value of food, e.g., golden rice, i.e., Vitamin ‘A’
enriched rice.
In addition to these uses, GM has been used to create tailor-made
plants to supply alternative resources to industries, in the form of starches,
fuels and pharmaceuticals.
Some of the applications of biotechnology in agriculture that you will
study in detail are the production of pest resistant plants, which could
decrease the amount of pesticide used. Bt toxin is produced by a
bacterium called Bacillus thuringiensis (Bt for short).  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: Some strains of Bacillus thuringiensis produce proteins that
kill certain insects such as lepidopterans (tobacco budworm, armyworm),
coleopterans (beetles) and dipterans (flies, mosquitoes).  B. thuringiensis
forms protein crystals during a particular phase of their growth. These
crystals contain a toxic insecticidal protein. Why does this toxin not kill
the Bacillus? Actually, the Bt toxin protein exist as inactive protoxins but
once an insect ingest the inactive toxin, it is converted into an active form
of toxin due to the alkaline pH of the gut which solubilise the crystals.
The activated toxin binds to the surface of midgut epithelial cells and
create pores that cause cell swelling and lysis and eventually cause death
of the insect.
2024-25
180
BIOLOGY
Specific Bt toxin genes were isolated from Bacillus thuringiensis and
incorporated into the several crop plants such as cotton (Figure 10.1).
The choice of genes depends upon the crop and the targeted pest, as
most Bt toxins are insect-group specific. The toxin is coded by a gene
cryIAc  named cry. There are a number of them, for example, the proteins
encoded by the genes cryIAc and cryIIAb control the cotton bollworms,
that of cryIAb controls corn borer.
Pest Resistant Plants: Several nematodes parasitise a wide variety of
plants and animals including human beings. A nematode Meloidegyne
incognitia infects the roots of tobacco plants and causes a great reduction
in yield. A novel strategy was adopted to prevent this infestation which
was based on the process of RNA interference (RNAi). RNAi takes place
in all eukaryotic organisms as a method of cellular defense. This method
involves silencing of a specific mRNA due to a complementary dsRNA
molecule that binds to and prevents translation of the mRNA (silencing).
The source of this  complementary RNA could be from an infection by
viruses having RNA genomes or mobile genetic elements (transposons)
that replicate via an RNA intermediate.
Using Agrobacterium vectors, nematode-specific genes were
introduced into the host plant (Figure 10.2). The introduction of DNA
was such that it produced both sense and anti-sense RNA in the host
cells. These two RNA’s being complementary to each other formed a double
stranded (dsRNA) that initiated RNAi and thus, silenced the specific mRNA
of the nematode. The consequence was that the parasite could not survive
in a transgenic host expressing specific interfering RNA. The transgenic
plant therefore got itself protected from the parasite (Figure 10.2).
Figure 10.1 Cotton boll: (a) destroyed by bollworms; (b) a fully mature
cotton boll
(b)
(a)
2024-25
Page 5


Biotechnology, as you would have learnt from the
previous chapter, essentially deals with industrial scale
production of biopharmaceuticals and biologicals using
genetically modified microbes, fungi, plants and animals.
The applications of biotechnology include therapeutics,
diagnostics, genetically modified crops for agriculture,
processed food, bioremediation, waste treatment, and
energy production. Three critical research areas of
biotechnology are:
(i) Providing the best catalyst in the form of improved
organism usually a microbe or pure enzyme.
(ii) Creating optimal conditions through engineering for
a catalyst to act, and
(iii) Downstream processing technologies to purify the
protein/organic compound.
Let us now learn how human beings have used
biotechnology to improve the quality of human life,
especially in the field of food production and health.
10.1 BIOTECHNOLOGICAL APPLICATIONS IN
AGRICULTURE
Let us take a look at the three options that can be thought
for increasing food production
(i) agro-chemical based agriculture;
CHAPTER 10
BIOTECHNOLOGY AND ITS
APPLICATIONS
10.1 Biotechnological
Applications in
Agriculture
10.2 Biotechnological
Applications in
Medicine
10.3 Transgenic Animals
10.4 Ethical Issues
2024-25
178
BIOLOGY
(ii) organic agriculture; and
(iii) genetically engineered crop-based agriculture.
The Green Revolution succeeded in tripling the food supply but yet
it was not enough to feed the growing human population. Increased yields
have partly been due to the use of improved crop varieties, but mainly
due to the use of better management practices and use of agrochemicals
(fertilisers and pesticides). However, for farmers in the developing world,
agrochemicals are often too expensive, and further increases in yield with
existing varieties are not possible using conventional breeding.
As traditional breeding techniques failed to keep pace with demand and
to provide sufficiently fast and efficient systems for crop improvement,
another technology called tissue culture got developed. What does
tissue culture mean? It was learnt by scientists, during 1950s, that
whole plants could be regenerated from explants, i.e., any part of a
plant taken out and grown in a test tube, under sterile conditions in
special nutrient media. This capacity to generate a whole plant from
any cell/explant is called totipotency. You will learn how to accomplish
this in higher classes. It is important to stress here that the nutrient
medium must provide a carbon source such as sucrose and also
inorganic salts, vitamins, amino acids and growth regulators like auxins,
cytokinins etc. By application of these methods it is possible to achieve
propagation of a large number of plants in very short durations. This
method of producing thousands of plants through tissue culture is
called micro-propagation. Each of these plants will be genetically
identical to the original plant from which they were grown, i.e., they are
somaclones.  Many important food plants like tomato, banana, apple,
etc., have been produced on commercial scale using this method. Try to
visit a tissue culture laboratory with your teacher to better understand
and appreciate the process.
Another important application of the method is the recovery of
healthy plants from diseased plants. 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.
Scientists have succeeded in culturing meristems of banana, sugarcane,
potato, etc.
Scientists have even isolated single cells from plants and after
digesting their cell walls have been able to isolate naked protoplasts
(surrounded by plasma membranes).  Isolated protoplasts from two
different varieties of plants – each having a desirable character – can be
fused to get hybrid protoplasts, which can be further grown to form a
new plant. These hybrids are called somatic hybrids while the process
2024-25
179
BIOTECHNOLOGY AND ITS APPLICATIONS
is called somatic hybridisation. Imagine a situation when a protoplast
of tomato is fused with that of potato, and then they are grown – to form
new hybrid plants combining tomato and potato characteristics. Well,
this has been achieved – resulting in formation of pomato; unfortunately
this plant did not have all the desired combination of characteristics for
its commercial utilisation.
Is there any alternative path that our understanding of genetics can
show so that farmers may obtain maximum yield from their fields? Is
there a way to minimise the use of fertilisers and chemicals so that their
harmful effects on the environment are reduced? Use of genetically
modified crops is a possible solution.
Plants, bacteria, fungi and animals whose genes have been altered by
manipulation are called Genetically Modified Organisms (GMO). GM
plants have been useful in many ways. Genetic modification has:
(i) made crops more tolerant to abiotic stresses (cold, drought, salt, heat).
(ii) reduced reliance on chemical pesticides (pest-resistant crops).
(iii) helped to reduce post harvest losses.
(iv) increased efficiency of mineral usage by plants (this prevents early
exhaustion of fertility of soil).
(v) enhanced nutritional value of food, e.g., golden rice, i.e., Vitamin ‘A’
enriched rice.
In addition to these uses, GM has been used to create tailor-made
plants to supply alternative resources to industries, in the form of starches,
fuels and pharmaceuticals.
Some of the applications of biotechnology in agriculture that you will
study in detail are the production of pest resistant plants, which could
decrease the amount of pesticide used. Bt toxin is produced by a
bacterium called Bacillus thuringiensis (Bt for short).  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: Some strains of Bacillus thuringiensis produce proteins that
kill certain insects such as lepidopterans (tobacco budworm, armyworm),
coleopterans (beetles) and dipterans (flies, mosquitoes).  B. thuringiensis
forms protein crystals during a particular phase of their growth. These
crystals contain a toxic insecticidal protein. Why does this toxin not kill
the Bacillus? Actually, the Bt toxin protein exist as inactive protoxins but
once an insect ingest the inactive toxin, it is converted into an active form
of toxin due to the alkaline pH of the gut which solubilise the crystals.
The activated toxin binds to the surface of midgut epithelial cells and
create pores that cause cell swelling and lysis and eventually cause death
of the insect.
2024-25
180
BIOLOGY
Specific Bt toxin genes were isolated from Bacillus thuringiensis and
incorporated into the several crop plants such as cotton (Figure 10.1).
The choice of genes depends upon the crop and the targeted pest, as
most Bt toxins are insect-group specific. The toxin is coded by a gene
cryIAc  named cry. There are a number of them, for example, the proteins
encoded by the genes cryIAc and cryIIAb control the cotton bollworms,
that of cryIAb controls corn borer.
Pest Resistant Plants: Several nematodes parasitise a wide variety of
plants and animals including human beings. A nematode Meloidegyne
incognitia infects the roots of tobacco plants and causes a great reduction
in yield. A novel strategy was adopted to prevent this infestation which
was based on the process of RNA interference (RNAi). RNAi takes place
in all eukaryotic organisms as a method of cellular defense. This method
involves silencing of a specific mRNA due to a complementary dsRNA
molecule that binds to and prevents translation of the mRNA (silencing).
The source of this  complementary RNA could be from an infection by
viruses having RNA genomes or mobile genetic elements (transposons)
that replicate via an RNA intermediate.
Using Agrobacterium vectors, nematode-specific genes were
introduced into the host plant (Figure 10.2). The introduction of DNA
was such that it produced both sense and anti-sense RNA in the host
cells. These two RNA’s being complementary to each other formed a double
stranded (dsRNA) that initiated RNAi and thus, silenced the specific mRNA
of the nematode. The consequence was that the parasite could not survive
in a transgenic host expressing specific interfering RNA. The transgenic
plant therefore got itself protected from the parasite (Figure 10.2).
Figure 10.1 Cotton boll: (a) destroyed by bollworms; (b) a fully mature
cotton boll
(b)
(a)
2024-25
181
BIOTECHNOLOGY AND ITS APPLICATIONS
10.2 BIOTECHNOLOGICAL APPLICATIONS IN MEDICINE
The recombinant DNA technological processes have made immense impact
in the area of healthcare by enabling mass production of safe and more
effective therapeutic drugs. Further, the recombinant therapeutics do not
induce unwanted immunological responses as is common in case of
similar products isolated from non-human sources. At present, about
30 recombinant therapeutics have been approved for human-use the
world over. In India, 12 of these are presently being marketed.
10.2.1 Genetically Engineered Insulin
Management of adult-onset diabetes is possible by taking insulin at
regular time intervals. What would a diabetic patient do if enough human-
insulin was not available? If you discuss this, you would soon realise
that one would have to isolate and use insulin from other animals. Would
the insulin isolated from other animals be just as effective as that
secreted by the human body itself and would it not elicit an immune
response in the human body? Now, imagine if bacterium were available
that could make human insulin. Suddenly the whole process becomes
so simple. You can easily grow a large quantity of the bacteria and make
as much insulin as you need.
Think about whether insulin can be orally administered to diabetic
people or not. Why?
Insulin used for diabetes was earlier extracted from pancreas of
slaughtered cattle and pigs. Insulin from an animal source, though caused
some patients to develop allergy or other types of reactions to the foreign
protein. Insulin consists of two short polypeptide chains: chain A
and chain B, that are linked together by disulphide bridges (Figure 10.3).
Figure 10.2 Host plant-generated dsRNA triggers protection against nematode infestation:
(a) Roots of a typical control plants; (b) transgenic plant roots 5 days after deliberate
infection of nematode but protected through novel mechanism.
(a) (b)
2024-25