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NCERT Solutions for Class 12 Biology Chapter 8
Human Health and Disease Class 12
Chapter 8 Human Health and Disease Exercise Solutions
Exercise : Solutions of Questions on Page Number : 164
Q1 :
What are the various public health measures, which you would suggest as safeguard against infectious
diseases?
Answer :
Public health measures are preventive measures which are taken to check the spread of various infectious diseases.
These measures should be taken to reduce the contact with infectious agents.
Some of these methods are:
(1) Maintenance of personal and public hygiene:It is one of the most important methods of preventing infectious
diseases. This measure includes maintaining a clean body, consumption of healthy and nutritious food, drinking clean
water, etc. Public hygienic includes proper disposal of waste material, excreta, periodic cleaning, and disinfection of
water reservoirs.
(2) Isolation: To prevent the spread of air-borne diseases such as pneumonia, chicken pox, tuberculosis, etc., it is
essential to keep the infected person in isolation to reduce the chances of spreading these diseases.
(3) Vaccination: Vaccination is the protection of the body from communicable diseases by administering some agent
that mimics the microbe inside the body. It helps in providing passive immunizationto the body. Several vaccines are
available against many diseases such as tetanus, polio, measles, mumps, etc.
(4) Vector Eradication: Various diseases such as malaria, filariasis, dengue, and chikungunya spread through
vectors. Thus, these diseases can be prevented by providing a clean environment and by preventing the breeding of
mosquitoes. This can be achieved by not allowing water to stagnate around residential areas. Also, measures like
regular cleaning of coolers, use of mosquito nets and insecticides such as malathion in drains, ponds, etc. can be
undertaken to ensure a healthy environment. Introducing fish such as Gambusia in ponds also controls the breeding
of mosquito larvae in stagnant water.
Q2 :
In which way has the study of biology helped us to control infectious diseases?
Answer :
Various advancements that have occurred in the field of biology have helped us gain a better understanding to fight
against various infectious diseases. Biology has helped us study the life cycle of various parasites, pathogens, and
vectors along with the modes of transmission of various diseases and the measures for controlling them. Vaccination
programmes against several infectious diseases such as small pox, chicken pox, tuberculosis, etc. have helped
eradicate these diseases. Biotechnology has helped in the preparation of newer and safer drugs and vaccines.
Antibiotics have also played an important role in treating infectious diseases.
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, www.ncrtsolutions.in
Q3 :
How does the transmission of each of the following diseases take place?
(a) Amoebiasis
(b) Malaria
(c) Ascariasis
(d) Pneumonia
Answer :
Disease Causative Mode of transmission
organism
a. Amoebiasis Entamoeba It is a vector-borne disease that spreads by the means of
histolytica contaminated food and water. The vector involved in the
transmission of this disease is the housefly.
b. Malaria Plasmodium sp. It is a vector-borne disease that spreads by the biting of the
female Anopheles mosquito.
c. Ascariasis Ascaris It spreads via contaminated food and water.
lumbricoides
d. Pneumonia Streptococcus It spreads by the sputum of an infected person.
pneumoniae
Q4 :
What measure would you take to prevent water-borne diseases?
Answer :
Water-borne diseases such as cholera, typhoid, hepatitis B, etc. spread by drinking contaminated water. These
water-borne diseases can be prevented by ensuring proper disposal of sewage, excreta, periodic cleaning. Also,
measures such as disinfecting community water reservoirs, boiling drinking water, etc. should be observed.
Q5 :
Discuss with your teacher what does 'a suitable gene' means, in the context of DNA vaccines.
Answer :
www.ncrtsolutions.in
NCERT Solutions for Class 12 Biology Chapter 8
Human Health and Disease Class 12
Chapter 8 Human Health and Disease Exercise Solutions
Exercise : Solutions of Questions on Page Number : 164
Q1 :
What are the various public health measures, which you would suggest as safeguard against infectious
diseases?
Answer :
Public health measures are preventive measures which are taken to check the spread of various infectious diseases.
These measures should be taken to reduce the contact with infectious agents.
Some of these methods are:
(1) Maintenance of personal and public hygiene:It is one of the most important methods of preventing infectious
diseases. This measure includes maintaining a clean body, consumption of healthy and nutritious food, drinking clean
water, etc. Public hygienic includes proper disposal of waste material, excreta, periodic cleaning, and disinfection of
water reservoirs.
(2) Isolation: To prevent the spread of air-borne diseases such as pneumonia, chicken pox, tuberculosis, etc., it is
essential to keep the infected person in isolation to reduce the chances of spreading these diseases.
(3) Vaccination: Vaccination is the protection of the body from communicable diseases by administering some agent
that mimics the microbe inside the body. It helps in providing passive immunizationto the body. Several vaccines are
available against many diseases such as tetanus, polio, measles, mumps, etc.
(4) Vector Eradication: Various diseases such as malaria, filariasis, dengue, and chikungunya spread through
vectors. Thus, these diseases can be prevented by providing a clean environment and by preventing the breeding of
mosquitoes. This can be achieved by not allowing water to stagnate around residential areas. Also, measures like
regular cleaning of coolers, use of mosquito nets and insecticides such as malathion in drains, ponds, etc. can be
undertaken to ensure a healthy environment. Introducing fish such as Gambusia in ponds also controls the breeding
of mosquito larvae in stagnant water.
Q2 :
In which way has the study of biology helped us to control infectious diseases?
Answer :
Various advancements that have occurred in the field of biology have helped us gain a better understanding to fight
against various infectious diseases. Biology has helped us study the life cycle of various parasites, pathogens, and
vectors along with the modes of transmission of various diseases and the measures for controlling them. Vaccination
programmes against several infectious diseases such as small pox, chicken pox, tuberculosis, etc. have helped
eradicate these diseases. Biotechnology has helped in the preparation of newer and safer drugs and vaccines.
Antibiotics have also played an important role in treating infectious diseases.
www.ncrtsolutions.in
, www.ncrtsolutions.in
Q3 :
How does the transmission of each of the following diseases take place?
(a) Amoebiasis
(b) Malaria
(c) Ascariasis
(d) Pneumonia
Answer :
Disease Causative Mode of transmission
organism
a. Amoebiasis Entamoeba It is a vector-borne disease that spreads by the means of
histolytica contaminated food and water. The vector involved in the
transmission of this disease is the housefly.
b. Malaria Plasmodium sp. It is a vector-borne disease that spreads by the biting of the
female Anopheles mosquito.
c. Ascariasis Ascaris It spreads via contaminated food and water.
lumbricoides
d. Pneumonia Streptococcus It spreads by the sputum of an infected person.
pneumoniae
Q4 :
What measure would you take to prevent water-borne diseases?
Answer :
Water-borne diseases such as cholera, typhoid, hepatitis B, etc. spread by drinking contaminated water. These
water-borne diseases can be prevented by ensuring proper disposal of sewage, excreta, periodic cleaning. Also,
measures such as disinfecting community water reservoirs, boiling drinking water, etc. should be observed.
Q5 :
Discuss with your teacher what does 'a suitable gene' means, in the context of DNA vaccines.
Answer :
www.ncrtsolutions.in
