1) The document is a presentation by Divyanshi Kherajani of class VIII-C about useful microorganisms. 2) It discusses the roles of decomposers like bacteria and fungi in breaking down dead organisms and recycling nutrients, as well as examples of helpful and harmful microbes. 3) Examples of helpful microbes include bacteria and yeasts that are used to make food products like cheese and bread, and fungi like penicillin that are used as medicines to kill harmful bacteria.

1. HOLY FAMILY CONVENT SR.
SEC. SCHOOL
Presentation On
Useful Micro-Organisms
Submitted to
Science Teacher
Submitted by
Divyanshi Kherajani
VIII-C

2. Review
• What is the role of decomposers in
the food chain?
• What are three different
types of decomposers?
VIDEO

5. Microorganisms
• Microorganisms are
living things you
cannot see without a
microscope.
• Some are helpful
while others are
harmful.

6. Helpful Microorganisms
• Bacteria live on and in our bodies and
keep us alive!

7. Helpful Bacteria
• Bacteria are used to
make cheese and
yogurt!
• Different types of
bacteria cause
different tastes!

8. Helpful Fungus
• Mold is a type of fungus.
• A mold called
penicillin is an
antibiotic
(medicine) we
take to kill bad
bacteria.

9. Bad bacteria
Penicillin

10. Helpful Fungus
• Yeast is another type of fungus.
• We use yeast when
baking bread
(releases CO2) and
to make wine
(creates ethanol).

11. Harmful Microorganisms
• Some microorganisms make us very
sick and destroy our food.

12. Harmful Bacteria
• Some types of bacteria are responsible
for sicknesses such as pneumonia and
food poisoning.

13. Harmful Fungus
• Fungus can
cause things
such as:
–Mold on food
–Athlete's Foot
–Dandruff

14. What’s growing on you!?
• Choose an area on your body where
you think a lot of microorganisms
would grow.
• Take a swab of that area and rub it on the
clear mixture in the bottle. Put your name on
the bottle and place it on the window sill.
• Square out an area in your notes and
explain why you think the body part you
chose will have the most microorganisms.