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Acknowledgement
I am overwhelmed in all humbleness and gratefulness to
acknowledge my depth to all those who helped me to put
these ideas, well above the level of simplicity and into
something concrete.

I would like to express my special thanks to gratitude to my

biology teacher., Mr. Satyendra Alha Sir as well as our
Principal Shri. Navina Kumar Srivastava Sir who gave me the
golden opportunity to do this wonderful project on the topic
“Common Disease in Human Body”, which also helped me in
doing a lot of research and I came to know about so many
things. I am really thankful to them.

Any attempt at any level can’t be satisfactorily completed

without the support and guidance of my Parents and Friends
who helped me a lot in gathering different information,
collecting data and guiding me from time to time in making
this project, despite of their busy schedule, they gave me
different ideas in making this project unique. I am thankful to
them too.
I am making this project not only for grades but also to
increase my knowledge.
Thanking you
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Contents
• Introduction
• Types of diseases
• Modes of transmission
• Viral diseases
• Bacterial diseases
• Protozoon diseases
• Conclusion
• Bibliography
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INTRODUCTION :
A disease is a condition of the body or a
part of it in which functions are disturbed
of maligned. Diseases may also be defined
as morphological, physiological,
psychological disturbance in the body or
body parts caused by some external
agencies which may be non-parasitic e.g.
deficiency of nutrients or may be Cars fie
caused by causes, bacteria, fungi etc. The
term disease means DIS- or discomfort. In
short it can be defined as 'disease is
disorder of body'.
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SOURCES OF DISEASES
The reservoirs of human diseases are:
a) Air: It is reservoir of pathogens of
many diseases like, measles,
tuberculosis, diphtheria etc.
b) Food and Water: These are reservoir
of pathogens of many diseases like,
cholera, polio, typhoid, roundworm,
tapeworm etc.
c) Soil: It is a reservoir of pathogen of
tetanus diseases.
d) Animals: These are those living
organisms which spread the pathogens
from also called reservoir host.

TYPES OF DISEASES :
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Diseases are broadly classified into two

categories:
A. Congenital Diseases :
Diseases present since birth and are
caused due to defective development of
inheritance e.g. congenital heart
diseases, haemophilia, colour blindness
etc.
B. Acquired diseases :
Diseases developed after birth. They
are further classified as-
a) Communicable diseases
b) Non-Communicable diseases

MODES OF TRANSMISSION OF
COMMUNICABLE DISEASES :
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The diseases are transmitted from the

reservoirs of infection to the healthy persons
the following ways:
1) Direct transmission: The pathogens are
transmitted from an infected person or
healthy person directly without an
intermediate agent. It occurs in following
ways-
a) Contact with soil e.g., tetanus.
2. Indirect transmission: The pathogens of
some diseases are carried through some
intermediate agents. It occurs in following
ways:
a) Air borne diseases.
b) By unclean hands and fingers.

VIRAL DISEASES
1. RABIES
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Rabies a fatal viral disease that is transmitted

to human beings by bite of rabid dog or cat.
A number of wild animals also carry the virus,
e.g. Jaundice wolves, foxes, bat, monkeys,
rabbit etc.
Symptoms: Rabies is 100% fatal disease. It is
characterized by high fever and pain
contraction of muscles of throat and chest.
The patient feels restless, has choking feet
and finds difficulty in taking even liquid food.
He is afraid of water, so called hydrophobia.
Prevention:
Dogs should be vaccinated with anti-rabies
vaccine.
Rabid animal should be killed, if it shows
excessive salivation and tries seeking
isolation.
Control: There is no treatment until now.
AIDS
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Aids stands for acquired immune deficiency

syndrome. It is caused by HIV (Human
immune-deficiency virus). It was firstly
detected in June 1981 in USA. This virus
weakness the human body's immunity or self
defense mechanism. Hence the aids virus
reduces the natural immunity of the human
body; therefore, the body saving AIDS
becomes prone to many other infections.
Modes of transmission:
It spreads through sexual contact with an
infected person carrying AIDS virus.
It spread though the transfusion of blood
infected with AIDS virus.

Symptoms: The important symptoms are-

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• Severe brain damage which may lead to

loss of memory, ability to speak and
think..
• Swollen lymph nodes.
• Sweating at night and weight loss.
• AIDS patient also become more
susceptible to infections of any body.
Prevention: No absolutely satisfactory vaccine
is yet available. So, we can prevent AIDS only
preventive measures like-
• Use of disposable syringes.
• Using condoms and adopt clean sex
habits.  People should be educated
about AIDS.
• Blood test must be done in pregnant
woman, blood donor's organ donors.
Control: A number of anti-malarial drugs are
available. The commonest anti- malarial drug
is quinine.
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BACTERIAL DISEASES
TYPHOID
Typhoid is caused by Salmonella typhoid
bacteria, commonly found in interterm of
man. This is common is age group of 1-15
years. Every year about 2.5 million people
suffer from typhoid.
Modes of transmission:
Contaminated food and water and house flies.
Symptoms: It is characterized by-
• Headache and rise in body temperature.
• Lesions of intestinal mucosa.
• Rose coloured rash on the
upper abdomen.
Prevention:
• Underground disposal of human faces. 
Typhoid is diagnosed by widal test.
Control: Antibiotics can treat the diseases.
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PROTOZOAN DISEASES
MALARIA
Malaria is more common in tropical and
subtropical countries, especially in Africa and
Asia. It is estimated that about 300 million
people are infected with malaria every year
and more than 2 million people die annually
due to this diseases.
Causes: Malaria is caused by the toxins
produced in the human body by the malaria
parasite Plasmodium. Presence of malarial
parasite can be checked by blood test.

Modes of transmission: Plasmodium of

transmitted by female Anopheles mosquito.
When this mosquito bites man to suck blood,
it introduces its saliva containing the malarial
parasite into the blood stream of the man.
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Symptoms: Malaria attack is preceded by

headache, nausea and muscular pain.
Total period of malarial attack is of 6-10 hour
and can be divided into 3 stages:
• Cold stage- Characterized by chilling and
shivering.
• Hot stage- Characterized by high fever,
faster rate of breathing and heart beat.
• Sweating stage. It is characterized by
lowering down of temperature to normal.
Prevention: Use of insect repellents to
prevent mosquito bite.
• Wire-gauzing of doors, windows, etc. to
check the entry of mosquitoes.
• Killing of adult mosquitoes by spraying
insecticides likes D.D.T and B.H.C.
Control : A number of anti-malaria drugs are
available.
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CANCER
It is the uncontrolled and unwanted growth of
cells.
Causes:
1. No definite cause has been arrived at so far.
However, it is found that body has
protooncogenes.
2. Heavy smoking and alcoholism.
3. Chewing of tobacco.
4. Consistent irritation of skin or repeated
injury at the same point. Cancer is a kind of
tumorous growth.
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Tumours can be classified into two categories:

a) Benign tumour: It remains confined to the
place of origin and does not spread to other
body parts.
b) Malignant tumour: It spreads to other
parts of the body and growth is rapid.
Symptoms:
1. Persistent lump or thickening in tissues,
especially in tongue, breast and uterus.
2. Any irregular bleeding or blood-tinged
discharge from anybody opening.
Prevention and cure:
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1. Cancer check up should be done once a

year.
2. Treatment should be taken under medical
advice.
3. Avoid smoking, taking alcohol and chewing
of tobacco.

Filariasis:
Pathogen: Filarial worm
Mode of transmission: Bites of mosquitoes -
Aedes and Culex.
Symptoms
1. Fever
2. Collection of endothelial cells and
metabolites in the wall of lymph vessels.
3. Swelling takes place in certain parts of the
body like legs, breasts & scrotum
Prevention and cure
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1. Mesh doors and windows in the house to

check the entry of mosquitoes. be properly
covered.
2. The water collected in tanks or other
articles should
3. Sprinkling of kerosene in ditches, etc.

CONCLUSION :
The diseases caused by intrinsic sources
are called organic or metabolic diseases
like cardiac failure, kidney failure,
diabetes, allergies, cancer etc and the
diseases caused by extrinsic factors are
Kwashiorkor, obesity, Night blindness,
scurvy etc. Some diseases are also caused
by micro-organisms due to unbalanced
diet such as viruses, bacteria, and fungi,
protozoan’s, worms, etc.; environmental
pollutants, tobacco, alcohol and narcotic
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drugs are also an important extrinsic

factors which upset human health.

BIBLIOGRAPHY :
 https://en.wikipedia.org
 NCERT textbook class XII
 www.khanacademy.com
 Lab manual
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Investigatory Project

Name :- Kishlay Vishlux

Class :- 12th A (Science)
Roll Number :-
School :- PM Shir Kendriya Vidyalaya EAC
upper Shillong Meghalaya
Subject :- Biology
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CERTIFICATE
This is to certify that original and genuine
work has been carried out to investigate
about the subject matter and related data
collection and investigation has been
completed sincerely and satisfactorily by
Kishlay Vishlux of class 12th of PM shri
kendriya Vidyalaya EAC upper Shillong
regarding her activity:

“Common Disease in Human Body”

Teacher’s Signature

External Examiner Signature