WHY
DO WE FALL ILL?
NCERT Textbook
Questions
Q.1.
State any two conditions essential for good health.
Answer.
Two
conditions essential for good health are
(i)
better sanitation or clean surroundings, and
(ii)
availability of sufficient and nutritious food.
Q.2.
State any two conditions essential for being free of disease.
Answer. (i)
Living in hygienic environment.
(ii)
Getting vaccinated against common infectious diseases.
Q.3.
Are the answers to the above questions necessarily the same or
different? Why?
Answer. Answers
of above questions (1, 2) are interconnected but different. It is
because being disease free does not mean is healthy.
Q.4.
List any three reasons why you would think that you are sick and
ought to see a doctor. If only one of these symptoms were present
would you still go to the doctor? Why or why not?
Answer. The
following three symptoms indicate our disease and urge us to go to
see doctor:
1.
having headache, shivering and body temperature
2.
having diarrhoea (loose-motions), and
3.
having a wound with pus.
If
only one of the above three symptoms were present, we still would
have to consult doctor. It is so because all the three symptoms made
us uncomfortable and bed-ridden for sometimes due to attack of some
diseases.
Q.5.
In which of the following cases do you think the long term effects on
your health are likely to be most unpleasant?
*
If you get jaundice;
*
If you get lice;
*
If you get acne. Why?
Answer. In
case of jaundice, there would be long term effects on our body.
Jaundice is the result of a disease called hepatitis,
caused
by a virus. In jaundice, our liver is affected and it takes more
contrast to jaundice, lice can be removed easily with short treatment
and so is the acne. Both of these do not produce long term effects on
the body.
Q.6.
Why we are normally advised to take bland and nourishing food when we
are sick?
Answer. When
we fall sick, one or more organ-systems do not function normally. As
a result, we lose appetite and do not have proper digestion and
absorption of food. Sickness makes us weak. Therefore, we are advised
to take bland and nourishing food during sickness. Such a food is
easily digested and replenish our lost vitamins, minerals and other
nutrients along with energy.
Q.7.
What are the different means by which infectious diseases are spread?
Answer. Infectious
diseases are generally spread through air, through water, through
sexual contact, through vectors (e.g.,
mosquito),
through physical contact with affected person, through articles or
formite borne (bedding, utensils, clothes, etc.) of use of affected
person.
Q.8.
What precautions can you take in your school to reduce the incidence
of infectious diseases?
Answer. Following
precautions can be taken in the school to reduce the incidence of
infectious diseases:
(i)
providing clean drinking water.
(ii)
educating students about causes of infectious diseases such as
cholera, hepatitis, flue, AIDS, etc.
(iii)
vaccination of students against common infectious diseases from time
to time.
(iv)
proper sanitation or clean environment in school and its surroundings
to eradicate vectors (e.g.,
mosquito)
of infectious diseases, and
(v)
by not allowing the affected students (e.g.,
a
student suffering from viral disease, called measles or chicken pox)
to attend the classes till they recover from infectious diseases.
Q.9.
What is immunisation?
Answer. If
one person has chicken pox once, there is no chance of suffering from
it again. This happens because when the immune system first sees an
infectious microbe, it responds against it and then remembers it
specifically. So the next time that particular microbe, or its close
relatives enter the body, the immune system responds with even
greater vigour. This eliminates the infection even more quickly than
the first time around. This is the basis of the principle of
immunization.
Q.10.
What are the immunization programmes available at the nearest health
centre in your locality? Which of these diseases are the major health
problems in your area?
Answer. At
the nearest public health centre in our locality, following childhood
immunisation programmes are available:
(i)
for preventing polio;
(ii)
for preventing tetanus, diptiheria and whooping cough;
(iii)
for preventing tuberculosis;
(iv)
for preventing measles.
Occasionally,
children suffer from measles in our area.
NCERT
Exercises
Q.1.
How many times did you fall ill in the last year? What are the
illness?
(a)
Think of any change you could make in your habits in order to avoid
any of most of the above illnesses.
(b)
Think of any change you would wish for in your surrounding in order
to avoid any of/most of the above illnesses.
Answer. Only
once I fell ill in the last one year. I suffered from sore throat and
cough.
(i)
I stopped drinking cold water immediately after taking food.
(ii)
Planting more trees, removing weeds and regular disposal of garbage.
Q.2.
A doctor/nurse/health-worker is exposed to more sick people then
others in the community. Find out how she/he avoids getting sick
herself/himself.
Answer. A
doctor/nurse/health-worker is exposed to more sick people in the
community. He avoids getting sick by:
(i)
keeping place of work sterilised by using phenyl, etc.
(ii)
keeping equipments, that are regularly in use, sterilised.
(iii)
washing hands with soap thoroughly after serious examination of
patients.
(iv)
wearing clean clothes.
Q.3.
Conduct a survey in your neighbourhood to find out what the three
most common diseases are. Suggest three steps that could be taken by
your local authorities to bring down the incidence of these diseases.
Answer. The
three most common diseases in my neighbourhood are:
(i)
Diarrhoea
(ii)
Cold and cough
(iii)
Typhoid.
Three
steps that should be taken by local authorities are:
(i)
providing clean drinking water regularly.
(ii)
providing better sanitation, i.e.,
clean
surroundings through regular disposal of garbage, and
(iii)
arranging immunisation programmes from time to time against common
infectious
Q.4.
A baby is not able to tell her/his caretakers that she/he is sick.
What would help us to find out
(a)
that baby is sick?
(b)
what is the sickness?
Answer. (a)
An extremely young human child is called baby. Symptoms that help us
to find that baby is sick, are
(i)
continuous crying and restlessness in the child.
(ii)
improper intake of food and body temperature;
(iii)
loose motions.
(b)
Baby is suffering from diarrhoea.
Q.5.
Under which of the following conditions is a person most likely to
fall sick?
(a)
when she is recovering from malaria,
(b)
when she has recovered from malaria and is taking care of someone
suffering from chicken pox.
(c)
when she is on a four-day fast after recovering from malaria and in
taking care of someone suffering from chicken-pox. Why?
Answer. (c)
Malaria is a very serious fatal disease. It is caused by the toxins
produced in the human body by malarial parasite Plasmodium
which
is carried from the infected person to the healthy persons by the
bite of the female Anopheles
mosquito.
Malaria results anaemia, enlargement of liver and spleen.
The
possible reason of falling sick of lady is that she has recently
suffered from malaria and her body’s organ systems are still not
functioning normally. Moreover, she is on four days fast which has
made her body weak due to improper supply of food. So, she is more
prone to infections. Above all, she is taking care of someone who is
suffering from most fearful infectious viral disease, i.e.,
chicken
pox, she has more chances of getting an infection due to above
mentioned regions.
Questions
Based on NCERT Question Bank (Exemplar Problems in Science)
Q.1.
What is disease? How many types of diseases have you studied? Give
examples.
Answer. Disease
(Old French disease
= lack
of ease)
is
a disorder
in a human, Animal or plant, caused by infection, diet or by faulty
functions of a process.
Types
of disease. (i)
On
the basis of duration. Acute
or chronic diseases.
(ii)
On
the basis of period of occurrence.
Congenital and acquired diseases.
(iii)
On
the basis of causal agents.
Infectious and non-infectious. Infectious or communicable diseases
can be contagious or non-contagious. Non-infectious disease may be
deficiency disease, metabolic disease, degenerative disease, allergy,
cancer and injury.
Example
of infectious disease. Influenza,
tuberculosis, pneumonia.
Example
of non-infectious disease. Cancer,
diabetes.
Q.2.
Give any four factors necessary for a healthy person.
Answer. (1)
Environment. (i)
A clean physical environment with the help of public health services.
(ii)
A congenial social environment.
(2)
Personal hygiene. Personal
cleanliness prevents catching up of infectious diseases.
(3)
Nourishment. Intake
of a proper balanced diet keeps the immune system strong.
(4)
Vaccination. Timely
vaccination against major disease (e.g.,
polio,
T.B., chicken pox, etc.) protects one self from catching those
diseases.
Q.3.
Give two examples for each of the following: (a) Acute diseases; (b)
Chronic diseases; (c) Infectious diseases; (d) Non-infectious
diseases.
Answer. (a)
Acute diseases. Typhoid,
Malaria, Influenza
(b)
Chronic diseases. Tuberculosis,
Elephantiasis
(c)
Infectious diseases. Typhoid,
Chicken pox
(d)
Non-infectious diseases. Diabetes,
Goitre.
Q.4.
Name two diseases caused by protozoans. What are their causal
organisms?
Answer. (a)
Sleeping
sickness caused by Trypanosoma
gambiense.
(b)
Malaria
caused by Plasmodium
vivax.
Q.5.
Which bacterium causes peptic ulcers? Who discovered the pathogen for
the first time?
Answer. Bacterium causing peptic ulcers. Helicobacter
pylori. Discovery.
Warren
(1984),
Marshal
and
Warren
(1985).
Q.6.
What are antibiotics? Give two examples.
Answer. Antibiotics.
An antibiotic is a biochemical produced by a microorganism (e.g.,
Bacteria
or fungi) which kills or block growth of other microorganisms
(pathogens) by blocking their life processes without harming human
cells, e.g.,
penicillin,
streptomycin.
Q.7.
Fill in the blanks
(a)
Pneumonia is an example of .................. disease.
(b)
Many skin diseases are caused by ..................
(c)
Antibiotics commonly block biochemical pathways important for the
growth of ..................
(d)
Living organisms carrying the infecting agents from one person to
another are called ..................
Answer. (a)
Infectious (communicable) disease;
(b)
fungi;
(c)
bacteria;
(d)
vectors.
Q.8.
Name the target organs of the following diseases:
(a)
Hepatitis targets ..................
(b)
Fit or unconsciousness targets ..................
(c)
Pneumonia targets ..................
(d)
Fungal disease targets ..................
Answer. (a)
Liver; (b)
Brain; (c)
Lungs; (d)
Skin.
Q.9.
(a)
Who discovered “vaccine” for the first time?
(b)
Name two diseases which can be prevented by using vaccines.
Answer. (a)
Edward Jenner; (b)
Tuberculosis (T.B.) and polio or tetanus and diphtheria.
Q.10.
Name any two groups of microorganisms from which antibiotics could be
extracted.
Answer. Bacteria,
Fungi.
Q.11.
Name any three diseases transmitted through vectors.
Answer. Malaria
(vector female Anopheles),
Dengue (vector female Aedes),
kala-azar (vector sandfly Phlebotomus).
Q.12.
Fill in the blanks:
(a)
.................. disease continues for many days and causes
.................. on body.
(b)
.................. disease continues for a few days and causes no
long term effect on body.
(c)
.................. is defined as physical, mental and social well
being and comfort.
(d)
Common cold is .................. disease.
(e)
Many skin diseases are caused by ..................
Answer. (a)
Chronic, long term effect; (b)
Acute; (c)
Health;
(d)
Infectious (communicable) or viral; (e)
Fungi.
Q.13.
Classify the following diseases as infectious and non-infectious:
(a)
AIDS; (b)
Tuberculosis; (c)
Cholera;
(d)
High blood pressure; (e)
Heart disease; (f)
Pneumonia;
(g)
Cancer.
Answer. (i)
Infectious diseases. AIDS,
Tuberculosis, Cholera.
(ii)
Non-Infectious diseases. High
blood pressure, Heart disease, Pneumonia, Cancer.
Q.14.
Explain giving reasons.
(a)
Balanced diet is necessary for maintaining healthy body.
(b)
Health of an organism depends upon the surrounding environmental
conditions.
(c)
Our surrounding area should be free of stagnant water.
(d)
Social harmony and good economic conditions are necessary for good
health.
Answer.
(a)
For keeping good health, we should eat a balanced diet containing
adequate (proportionate) amounts of all the essential nutrients such
as carbohydrates, proteins, fats (lipids), vitamins, minerals, water
and roughage. Unbalanced diet causes malnutrition. Proper nourishment
maintains the health of all the body systems including the immune
system.
(b)
Health of an organism including human beings depend upon the
surrounding environmental conditions. Public
Health Services ensure
clean environment around our dwellings and protection from outbreak
of diseases. They ensure removal of garbage, drainage and sewage
services, proper drinking water, unadulterated food articles, vector
and pest control, vaccination and other health care services. If
these services are insufficient or faulty, the health of individual
citizens is bound to be adversely affected despite taking the best
balanced food and keeping the best personal hygiene. It is because,
infection is contracted from others and is connected with
uncontaminated food.
(c)
Stagnant water (of pools, ponds) is habitat of larvae of many types
of mosquitoes. It is also source of many water borne diseases.
Therefore, stagnant water should not be present in and around human
habitations.
(d)
(i)
Social equality and harmony are required for participating in one
another’s joys and sorrows, helping the others and receiving help
at the time of need. There should not be any sort of mistrust, worry
and mistreatment of each other. This would make everybody in the
community happy and healthy.
(ii)
A proper nutrition is essential for good health. Poverty is the root
cause of nutritional disorders (i.e.,
malnutrition
and under nourishment) in our country. There should be proper earning
in order to provide food to every one in the family. For a good
earning there should be opportunity for a proper job for which the
bread earner has been trained. Therefore, a proper training for job,
a good job and subsequently good economic conditions are needed to
maintain health of the individuals.
Q.15.
What do you mean by disease symptoms? Explain giving two examples.
Answer. Disease symptoms are
evidences of presence of diseases. Symptoms are in the form of
structural and functional changes in the body or body parts. They
indicate that there is something wrong in the body, e.g.,
wound
with pus, oedema, cough, cold, loose motions, pain in abdomen,
headache, fever. However symptoms do not give any exact cause of the
disease. For instance, headache may be due to some dozen different
diseases. There may be problem of eye sight, blood pressure, some
sort of stress (such as of examination, meningitis, pollution, etc.).
Q.16.
Why is immune system essential for our health?
Answer. Immune
system is body defence system against various types of pathogens. It
includes following components of blood-phagocytic cells, natural
killer cells (NK cells), T-lymphocytes and B-lymphocytes.
B-lymphocytes produce antibodies against antigens of pathogens and
their toxins. Immune system keeps the body healthy by killing
infecting microbes.
Q.17.
Why is AIDS considered to be a “syndrome” and not a disease?
Answer. Syndrome is
a group of symptoms, signs, physical and physiological disturbances
that are due to a common cause. AIDS is also a complex of diseases
and symptoms which develop due to failure of the body to fight off
even minor infections. HIV that causes AIDS damages immune system of
the patient by destroying T4
helper
cells (T lymphocytes). As a result, even small cold leads to
development of pneumonia, a slight gut infection leads to severe
diarrhoea and blood loss, likewise skin rashes develop into ulcers.
Q.18.
Why do some children fall ill more frequently than others living in
the same locality?
Answer. Children
fall ill more frequently due to (i)
poor personal hygiene; (ii)
poor domestic hygiene; (iii)
unclean food; (iv)
lack of proper nutrition and balanced diet. All these factors make
the immune system weak.
Q.19.
What precautions would you take to justify “prevention is better
than cure”
Answer. Prevention
is better than cure as a disease always causes some damage to the
body, loss of working days, besides expenditure on medication. The
important precautions for preventing occurrence of diseases include
(i)
hygienic environment; (ii)
personal hygiene; (iii)
proper nutrition (balanced diet); (iv)
clean food; (v)
clean water; (vi)
regular exercise and (vii)
adequate relaxation. Every body should also be aware of diseases and
their mode of spreading (epidemic). A regular medical check-up is
also earnestly required to stay healthy.
Q.20.
Why are antibiotics not effective for viral diseases?
Answer. Antibiotics
are effective against bacteria and other non-viral pathogens as they
block some of their biosynthetic pathways without affecting human
beings. However, viruses do not have their own metabolic machinery.
There are very few biochemical processes that can block viral
multiplication. Antibiotics are not effective against them. They can
be overpowered only by development of immunity against them, by the
body the host. An antiviral product, called interferon
is
produced by the cells exposed to the action of virus.
Q.21.
Becoming exposed to or infected with a microbe does not necessarily
mean developing noticeable disease. Explain.
Answer. An
infectious microbe is able to cause a disease only if the immune
system of the infected person is unable to put proper defence against
it. Many persons have strong immune system or have acquired immunity
against the pathogen or the intensity of pathogenic attack is quite
mild. As a result, despite exposure to infective microbe, the person
will not catch the disease
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