Class 8, Chapter 2- Micro-Organisms, Lesson- 2

2. MEDICINAL USE OF
MICRO-ORGANISMS

3. RECALL

4. COMMERCIAL USE

5. Q1. Which bacterium helps in the formation of
curd?
(i) Lacto bacillus (ii) Escherichia coli
(iii) Spirillum volutans (iv) Vibrio cholerae
Q2. The process of conversion of sugar into
alcohol is called:
(i) nitrogen fixation (ii) moulding
(iii) fermentation (iv) infection

7. WHY DO WE TAKE MEDICINE?

8. SOURCE?

9. MEDICINAL USE OF MICRO-
ORGANISMS
• Source of the medicines  Micro-organisms
• The medicines that kill or stop the growth of
the disease-causing microorganisms in our
body are called antibiotics.
• A number of antibiotics are produced from
bacteria and fungi.

10. Streptomycin, tetracycline and erythromycin
are some of the commonly known antibiotics
which are made from fungi and bacteria.

11. • The antibiotics are manufactured by growing
specific microorganisms and are used to cure
a variety of diseases.
• Antibiotics are even mixed with the feed of
livestock to check microbial infection in
animals.
• They are also used to control many plant
diseases.

12. Poll:
Q1.The following is an antibiotic
(i) Sodium bicarbonate (ii) Streptomycin
(iii) Alcohol (iv) Yeast
Q2. Antibiotics mixed with the feed of livestock
helps to check microbial infection in:
(i)human beings (ii)birds
(iii)animals (iv)fishes

14. Why do you think children vaccinated with
polio drops do not get polio ever again but
those who have not been vaccinated get
affected with polio?

15. VACCINE
A fluid/medicine that helps our body
to become immune to a disease
caused by certain germs.

17. Diseases, including cholera, tuberculosis,
smallpox and hepatitis can be prevented by
vaccination.

18. • These days vaccines
are made on a large
scale from micro-
organisms to protect
humans and other
animals from several
diseases.
• One of the biggest
examples is the
mass production of
covaxin and
covishield.

19. Poll:
Q1.When a disease-carrying microbe enters our
body the body produces ______ to fight the
invader.
(a)antibodies
(b)antigens

20. What would have happened if any
medicine or vaccine would not have been
discovered?

21. • In 1929, Alexander Fleming
was working on a culture of
disease causing bacteria.
• Suddenly he found the
spores of a little green mould
in one of his culture plates.
• He observed that the
presence of mould
prevented the growth of
bacteria.
• In fact, it also killed many of
these bacteria. From this the
mould penicillin was
prepared.
Alexander Fleming

22. Edward Jenner
discovered the vaccine
for smallpox in 1798.
Edward Jenner

23. Poll:
Q1.When was Penicillin discovered?
(a)1987
(b)1929
(c)1945
(d)1971

25. Tabulate the differences between antibiotics
and vaccine with appropriate examples.
ANTIBIOTICS VACCINE
DEFINITION
MADE FOR
EXAMPLES

26. HOMEWORK
Q1. Visit a doctor. Find out why antibiotics
should not be overused. Prepare a short report.
Q2. Prepare a list of all the diseases against
which you have been vaccinated along with the
micro-organisms that causes the particular
disease.
Q3. Write 10 lines on the usefulness of
microorganisms in our lives.
Q4.Watch You Tube video on how Edward
Jenner discovered small pox vaccine.