1. Lesson 5.3
SCIENCE HELPS
PEOPLE PREVENT AND
TREAT DISEASES.

2. Introduction:
 Flu , influenza, chicken pox and hepatitis
are all kinds of diseases.
 DISEASE is a change that disturbs the
normal functioning of your body.
 Diseases are caused by
MICROORGANISMS .
 Microorganisms cant be seen by our
nacked eye.

3. 1-So the discovery
of the microscope
was a great event in
science. It helped
scientists to detect
the cause of
diseases.
FIRST MICROSCOPE

4. second
 Understanding diseases and studying
them helped in PREVENTION and
TREATMENT of many illnesses….

5. SCIENCE
 The effort done by many scientists
lead them reach the theory which says
“Infectious diseases are caused by
germs.”
Food decay was a clear view to study
the presence of germs.

6. GERMS could be:
 A- Bacteria
 B- Viruses
 C- Fungi
 D- Protists

7. BACTERIA
 Deff: are single
celled organisms
that can live every
where

9. Bacteria growing in agar an seen
under microscope

10. Bacteria
 Some bacteria like that found in the
normal flora of our intestine can be
helpful , it helps in certain food
digestion.
 Other bacteria are harmful causing
diseases like : pneumonia , ear
infection and strep throat.

11. Dividing Bacteria

12.  In the previous centuries people used
to die from diseases considered
nowadays as very easy curable ones,,
 Also they used to die after successful
surgeries due to simple infections..
 Later on doctors understood the germ
theory of PASTUER which is
“Diseases are caused by GERMS”

13.  Nowadays
infections due to
bacteria are treated
ay ANTIBIOTICS .
Which was a major
turnpoint in
medicine..

14. Other facts
 Other than medicines people are
getting use of bacteria in industry by
producing dairy products, vinegar ,
and in sewage disposal to clean up
organic wastes..
 Biologists are also using bacteria to
perform their experiments and
produce certain useful proteins using
the bacteria’s body and viruses them
selves. eg : production of insulin for
diabetic people.

15. VIRUSES
 Cant be considered
as living things
since it must enter
living cells and get
use of its DNA in
order to reproduce.
 Example: stomach
flu and colds.

16. VIRUSES forms

17. Dividing viruses

18. Viruses could also infect:
computers

19. And….. cellphones

20. TREATING INFECTIOUS
diseases
 ALEXANDER FLEMING was growing
bacteria in agar plates where he saw
clear area around a mold.
 So by accident Fleming discovered
the cure against bacterial infections
which is now known as
“ANTIBIOTICS’’ …

21. FLEMING

22. SO
 Penicillin is a substance produced by
molds (kind of fungus) and serves as
antibiotic which is a cure for bacterial
infections not viral ones.

23. How does infectious diseases
spread?
 Food, air and water.
 Contact with animals
 Person-to-person contact

24. Food, air and water
 Pathogens could be found any where
so people must take the correct
precautions to prevent the spread of
bacteria and viruses especially those
responsible of contagious diseases..
 Precautions to take::::::::::::::;

25. Cover your mouth when you
cough or sneeze.
 To prevent the
spread of
viruses to the
surrounding air

26. Wash fruits and vegetables very
well

27. Since high temperature kills germs
Cook the meat and egg

28. Purify the water
 Either by adding
chlorine or by
boiling the water or
simply by using
filters.

29. Contact with animals
 Animals’ fur, breath and saliva could
carry millions of bacteria.example:
 1- rabies “ a deadly central nervous
system disease” it’s a disease that
inhabits the saliva of infected animals
like raccoon or opossum..
 The veterinarian can give your pet
injections to prevent rabies.
 2-worms also could pass from animals
through our mouth or nose and enter to
live in lour intestine.
 3-fungus could cause us ringworms
infection

30. Different types of animal
contact

32. Person-to-person contact
 People are another area for
pathogens to pass through so
whenever you touch someone a
pathogen is transmitted either through
skin, mouth nose eyes or cuts.
 Simplest way to avoid receiving these
pathogens is to wash your hands often
and very well..
 A daily bath and wash well your
clothes.

33. WASHHHHHH

34. Some examples about
pathogens and diseases
 E .coli it’s a
bacteria causing E
coli poisoning.
 Prevention: Wash
well fruits
,vegetables and
cook meat.

35. How is E coli transmitted

36. giardiasis
 Caused by giardia
lamblia which is a
protozoa, caused
by contaminated
water and close
contact with
infected people

37. It seems to have a smiley
face 

38. The deer tick
 It a bacteria that
causes the LYME
disease coming
from a tick bite.
Use repellents
containing
DEET.(it’s a yellow
oil which repels
ticks)

39. LYME disease

40. Noninfectious diseases are not
contagious.
 These diseases do not spread by
pathogens, some exist at birth while
others develop during life.
 Therefore some are INHERETED
diseases while others are LIFESTYLE
diseases.

41. Diseases present at birth
 These diseases are transmitted from
parents to their children through
GENES.
 Defected genes code for cells that do
not function properly.
 Usually genetic disorders come from
recessive forms, which means the
parents are normal while their kids
hold the defected trait.eg: cystic
fibrosis and sickle cell anemia.

42. RECESSIVE TRAITS

43. Cystic fibrosis: viscous secretion
in the lungs.

44. Sickle cell anemia: poor oxygen
supply

45. Huntington disease
 Its symptoms are
not immediately
present after birth
but at adulthood
stage: it affect
muscle
coordination.

46. TALIPES or CLUB FOOT
 Is due to the
improper
development of
bones of the leg
and foot. Its fixed
through a surgery
after birth.

47. Disease in later life
 Environmental conditions as well as our
lifestyle both play a great role in the
quality of our health and life length.
 so we must maintain a proper healthy life
style including good nutriton,exercise
and escape from harmful material , in
order to avoid chronic diseases such as
heart, lung diseases and cancer.
 People with family histories of cancer
must be highly aware of environmental
conditions like tar and other chemicals
that could increase their risk of initiating
cancer.

48. Scientists continue efforts to
prevent and treat diseases.
Even though scientists reached a great
effort in understanding and treating
diseases yet diseases are still a
problem all over the world.
We have many progressive
achievements
Like:
Antibiotics and vaccinations BUT
On the other hand new illnesses and
viruses are appearing with no known

49. Example:
 AIDS :loss of
immunity and
eventually death.

50. Nile virus
 Transmitted
through a mosquito
bite and causes the
brain inflammation.

51. Other problems
 The excessive use of antibiotics to a
certain type of bacteria will develop
“RESISTANCE” which means that the
bacteria strain is no longer affected by
this drug.
 This resistance is passed to the next
generations.

52. THE END