Chapter 9: Applications of Genetics
2 marks:
1.
What is genetic counseling?
Ans:
i.
Genetic counseling is the process of hwlping people to
understand and cope up with the medical, psychological and familial
implications of the genetic diseases.
ii.
It is of two types:
a.
Prospective counseling
b.
Retrospective counseling
2.
What is genetic engineering?
Ans:
i.
Manipulation in the genetic make-up of an organism is called as
genetic engineering.
ii.
The organism is called as genetically engineered organism.
3.
Explain cloning.
Ans:
i.
It is a process in which exact copy of the original gene or
organism is prepared.
ii.
Cloning can be limited to genetic level or even organisms i.e.
plants and animals can also be cloned e.g. Dolly sheep.
4.
What is restriction enzyme?
Ans:
i.
It is an enzyme which cuts the double stranded DNA molecule.
ii.
It is also called as “Molecular scissor”
iii.
It cuts the DNA in middle of the strand
5.
What are vectors?
Ans:
i.
Vectors are the molecules which carry the DNA from one organism
to another
ii.
e.g. Plasmid DNA
6.
Explain tandem repeats.
Ans:
i.
It is the segment of DNA containing identical or repetitive DNA
sequences.
ii.
The pattern, length and number of repeats are unique for each
individual.
7.
What is DNA fingerprinting?
Ans:
i.
It is a unique identification test which utilizes genetic
differences to differentiate between people
ii.
It is commonly used in forensic science.
8.
What is gene therapy?
Ans:
i.
It is a therapy used to treat genetic diseases.
ii.
In this therapy, the diseased gene is replaced by a healthy
gene.
9.
What is eugenics?
Ans:
i.
It is a science which deals with all influences that improve the
inborn qualities of a race.
ii.
It is of two types:
a)
Positive eugenics
b)
Negative eugenics
10.What is plasmid?
Ans:
i.
It is extra chromosomal, double stranded circular DNA molecule found
in bacterial cell
ii.
It is extensively used in genetic engineering
4 marks:
1.
What is genetic counseling? Explain its types.
Ans:
i.
Genetic counseling is the process of helping people to
understand and cope up with the medical, psychological and familial
implications of the genetic diseases.
ii.
It is of two types:
a.
Prospective counseling:
§ This type of counseling
is given to the parents or couple during first pregnancy or even before
pregnancy.
§ It is generally given to the couples with
family history ofsome genetic defects.
b.
Retrospective
counseling:
§ This type of counseling
is given to parents who already have a child with some genetic disease.
§ Such counseling is given to help the parents
in managing the genetically diseased child, coping with the emotional stress and
to ensure that their other children born later are disease free.
2.
What is genetic engineering? Add a note on the steps involved in
it.
Ans:
i.
Manipulation in genetic make up of the organism is called as
genetic engineering.
ii.
Steps involved in genetic engineering (taking example of gene
cloning:
a.
The gene of interest is selected and isolated.
b.
A bacterial host system is selected.
c.
Plasmid DNA is isolated from the selected bacteria.
d.
Plasmid DNA is opened using restriction enzyme.
e.
The gene of interest is inserted in the plasmid DNA and joined
with help of DNA ligase enzyme.
f.
The plasmid DNA formed after insertion of gene of interest is
called as recombinant plasmid DNA.
g.
This recombinant plasmid DNA is inserted in the selected
bacterial cells.
h.
As the bacterial cells multiply, the gene of interest also
multiplies and multiple copies of gene of interest is formed i.e. gene of
interest is cloned.
3.
Describe the process of cloning.
Ans:
i. The gene of interest is selected and isolated.
ii. A bacterial host system is selected.
iii. Plasmid DNA is isolated from the selected bacteria.
iv. Plasmid DNA is opened using restriction enzyme.
v. The gene of interest is inserted in the plasmid DNA and joined
with help of DNA ligase enzyme.
vi. The plasmid DNA formed after insertion of gene of interest is
called as recombinant plasmid DNA.
vii. This recombinant plasmid DNA is inserted in the selected
bacterial cells.
viii.As the bacterial cells multiply, the gene of interest also
multiplies and multiple copies of gene of interest is formed i.e. gene of
interest is cloned.
4.
Explain the process of DNA fingerprinting.
Ans:
i.
Cells or tissue from which DNA could be isolated is taken
ii.
DNA is cut into fragments using restriction enzymes
iii.
The fragments of DNA are separated by the process of gel
electrophoresis.
iv.
The pattern of fragments formed is transferred to a nylon membrane
v.
Radioactive DNA probe is added.
vi.
The DNA probe attaches to its complimentary DNA fragment.
vii.
Excess probe is washed away.
viii.
The radioactive DNA pattern autoradiographed using X- rays.
ix.
When the film is developed after X- ray exposure, a visible DNA
fingerprint is formed.
5.
Explain the principle of DNA fingerprinting.
Ans:
i.
DNA fingerprinting process was first given by Sir Alec Jeffery.
ii.
This process is based upon the fact that, DNA of all individuals
is unique (except identical twins).
iii.
DNA in all individuals is interrupted by a series of identical
DNA sequences called as repetitive DNA or tandem repeats.
iv.
The pattern, length and number of nucleotides in this repeat
sequence varies from person to person.
v.
Thus, by detecting the tandem repeats and observing the
difference amongst them, one can differentiate between any two individuals.
6.
What is gene therapy? Explain its types.
Ans:
i.
It is a therapy used to treat genetic diseases.
ii.
In this therapy, the diseased gene is replaced by a healthy
gene.
iii.
Following are the types of gene therapies:
a)
Targeted gene therapy:
·
Genes are introduced by traditional gene transfer methods.
·
The important part is the healthy gene gets incorporated at a
specific site i.e. random insertion of healthy gene is not there.
b)
Augmented gene therapy:
·
In this method, many copies of healthy genes are introduced in
the cell
·
There is no specific site for incorporation of the healthy gene.
7.
What is eugenics? Add a note on its types.
Ans:
i.
Eugenics is a science which deals with all influences that
improve the inborn qualities of a race.
ii.
Types of eugenics:
a)
Positive eugenics:
·
In this approach, measures are taken to increase the frequency
of desirable traits.
·
It can be achieved by providing better education, chance to
select desirable match, improving genetic research etc.
b)
Negative eugenics:
·
In this approach, measures are taken to decrease the frequency
of undesirable traits.
·
It can be achieved by restricting consanguineous marriages,
control on immigration, etc.
8.
What are the applications of genetic engineering?
Ans:
i.
Engineering of bacteria to carry out specific processes or to
produce important molecules such as hormones and antibiotics.
ii.
Altering the genotypes of plants as an aid in plant breeding
iii.
Altering of animals so as to produce human therapeutic products.
iv.
DNA fingerprinting
v.
Gene therapy
8 marks:
1.
Describe genetic counseling.
Ans:
i.
Genetic counseling is the process of helping people to
understand and cope up with the medical, psychological and familial
implications of the genetic diseases.
ii.
It involves providing specific counseling to people having or
expecting genetic problems in their family.
iii.
The aim of genetic counseling is to help people in making responsible
decision so as to form a disease free society.
iv.
It is of two types:
a.
Prospective counseling
b.
Retrospective
counseling
v.
Prospective counseling
§ This type of counseling
is given to the parents or couple during first pregnancy or even before
pregnancy.
§ It is generally given to the couples with
family history of some genetic defects.
vi.
Retrospective
counseling
§ This type of counseling
is given to parents who already have a child with some genetic disease.
§ Such counseling is
given to help the parents in managing the genetically diseased child, coping
with the emotional stress and to ensure that their other children born later
are disease free.
2.
Explain the principle and process of DNA fingerprinting.
Ans:
Principle of DNA
fingerprinting:
i.
DNA fingerprinting process was first given by Sir Alec Jeffery.
ii.
This process is based upon the fact that, DNA of all individuals
is unique (except identical twins).
iii.
DNA in all individuals is interrupted by a series of identical
DNA sequences called as repetitive DNA or tandem repeats.
iv.
The pattern, length and number of nucleotides in this repeat
sequence varies from person to person.
v.
Thus, by detecting the tandem repeats and observing the
difference amongst them, one can differentiate between any two individuals.
Process of DNA
fingerprinting:
i.
Cells or tissue from which DNA could be isolated is taken
ii.
DNA is cut into fragments using restriction enzymes
iii.
The fragments of DNA are separated by the process of gel
electrophoresis.
iv.
The pattern of fragments formed is transferred to a nylon membrane
v.
Radioactive DNA probe is added.
vi.
The DNA probe attaches to its complimentary DNA fragment.
vii.
Excess probe is washed away.
viii.
The radioactive DNA pattern autoradiographed using X- rays.
ix.
When the film is developed after X- ray exposure, a visible DNA
fingerprint is formed.
3.
What is positive eugenics? Explain.
Ans:
i.
It is strategy of eugenics which focuses on increasing the
frequency of desirable traits amongst population
ii.
There are following aspects considered in positive eugenics:
a)
Better education: people should be
educated about basics of human biology and genetics. Understanding genetic
diseases and their long term effects would help further in eliminating these
diseases.
b)
Social hindrance: selection of right
partner is not allowed in many societies due to social compulsions. Marriages between
individuals of different castes or communities is prohibited which in turn
results in restriction in mixing of good germplasm.
c)
Subsidizing the fit: Galton has suggested that
a few selected men and women of good eugenic value should be encouraged to
increase their birth rate. Such parents must be granted with family allowances
and relief of taxation etc.
d)
Immigration: immigration in a
country is one of the factors that influences the frequency of a particular
gene in population. Thus, there should be controlled immigration.
e)
Improvement of
environmental conditions: environment plays important role in expression of certain
genes. In such case, good environmental conditions such as better school
facilities, training, medical aids, nutrition, good living conditions etc.
should be provided to the people.
4.
What is negative eugenics? Explain.
Ans:
§ It is strategy of
eugenics which focuses on decreasing the frequency of undesirable traits
amongst population
§ Following are some
important aspects considered in negative eugenics:
a)
Restriction on marriage:
there should be
restrictions on consanguineous marriages i.e. marriages within close relations.
Close relatives have same parental stock genes from at least two generations
before. Thus, chances of diseases in children born from such marriages are more
.
b)
Control on
immigration: immigrants should be controlled so as to eliminate any bad
genetic pool mixing with the present gene pool of the country.
c)
Sterlization: people with defective
germplasm should be sterilized so as to control of stop the flow of defective
germplasm in future generations.
d)
Segregation: individuals suffering
from psychological diseases should be isolated from the society and should not
be allowed to marry or reproduce so that the hereditary defective genes are not
passed on to the future generation.
16 marks:
1. What is positive
eugenics? Explain.
Ans:
§ It is strategy of
eugenics which focuses on increasing the frequency of desirable traits amongst
population
§ There are following
aspects considered in positive eugenics:
a)
Better education: people should be
educated about basics of human biology and genetics. Understanding genetic
diseases and their long term effects would help further in eliminating these
diseases.
b)
Social hindrance: selection of right
partner is not allowed in many societies due to social compulsions. Marriages between
individuals of different castes or communities is prohibited which in turn
results in restriction in mixing of good germplasm.
c)
Subsidizing the fit: Galton has suggested that
a few selected men and women of good eugenic value should be encouraged to
increase their birth rate. Such parents must be granted with family allowances
and relief of taxation etc.
d)
Immigration: immigration in a
country is one of the factors that influences the frequency of a particular
gene in population. Thus, there should be controlled immigration.
e)
Improvement of
environmental conditions: environment plays important role in expression of certain
genes. In such case, good environmental conditions such as better school
facilities, training, medical aids, nutrition, good living conditions etc.
should be provided to the people.
f)
Prevention of germinal
waste:
due to social hindrance or death of individuals with good germplasm, loss of good
gene pool takes place.
g)
Genetic research: though there has been
sufficient research on human heredity still this education has not reached to
common people. Thus, further knowledge to all people is required. Also, genetic
research should continue for betterment of human race.
2. What is eugenics?
Explain its types.
Ans:
i.
It is a science which deals with all influences that improve the
inborn qualities of a race.
ii.
It is of two types:
c)
Positive eugenics
d)
Negative eugenics
iii.
Positive Eugenics:
§ It is strategy of
eugenics which focuses on increasing the frequency of desirable traits amongst
population
§ There are following
aspects considered in positive eugenics:
a)
Better education: people should be
educated about basics of human biology and genetics. Understanding genetic
diseases and their long term effects would help further in eliminating these
diseases.
b)
Social hindrance: selection of right
partner is not allowed in many societies due to social compulsions. Marriages between
individuals of different castes or communities is prohibited which in turn
results in restriction in mixing of good germplasm.
c)
Subsidizing the fit: Galton has suggested that
a few selected men and women of good eugenic value should be encouraged to
increase their birth rate. Such parents must be granted with family allowances
and relief of taxation etc.
d)
Immigration: immigration in a
country is one of the factors that influences the frequency of a particular
gene in population. Thus, there should be controlled immigration.
e)
Improvement of
environmental conditions: environment plays important role in expression of certain
genes. In such case, good environmental conditions such as better school
facilities, training, medical aids, nutrition, good living conditions etc.
should be provided to the people.
f)
Prevention of germinal
waste:
due to social hindrance or death of individuals with good germplasm, loss of good
gene pool takes place.
g)
Genetic research: though there has been
sufficient research on human heredity still this education has not reached to
common people. Thus, further knowledge to all people is required. Also, genetic
research should continue for betterment of human race.
iv.
Negative
Eugenics:
§ It is strategy of
eugenics which focuses on decreasing the frequency of undesirable traits
amongst population
§ Following are some
important aspects considered in negative eugenics:
a)
Restriction on marriage:
there should be
restrictions on consanguineous marriages i.e. marriages within close relations.
Close relatives have same parental stock genes from at least two generations
before. Thus, chances of diseases in children born from such marriages are more
.
b)
Control on
immigration: immigrants should be controlled so as to eliminate any bad
genetic pool mixing with the present gene pool of the country.
c)
Sterlization: people with defective
germplasm should be sterilized so as to control of stop the flow of defective
germplasm in future generations.
d)
Segregation: individuals suffering
from psychological diseases should be isolated from the society and should not
be allowed to marry or reproduce so that the hereditary defective genes are not
passed on to the future generation.
Comments
Post a Comment