Life Sciences-Microorganisms (Bacteria, Fungi, Virus, Protista)

Slides focusing on microorganisms which include: virus, bacteria, fungi and prostista

1. MICROORGA
-NISMS
U TSHOKO 223205538
TEACHING STUDIES 3B

2. GENERAL CHARACTERISTIC
OF
MICRO-ORGANISMS

3. 1. MICROSCOPIC
•Micro-organisms are very
small in size.
•They cannot be seen with
naked eye.
•To see them a microscope is
needed.

4. UNICELLULAR MULTICELLULAR
Bacteria
Fungi-
Mushroom
2. CELLULAR STRUCTURE
•Micro-organisms can either be unicellular or multicellular.
•Unicellular means single celled.
•Multicellular means multiple cells.

5. Bacteria
Protista-
Amoeba
3. Prokaryotic or Eukaryotic
•Prokaryotic micro-organisms lack membrane-bound organelles such as
mitochondrion.
•Eukaryotic organisms have membrane-bound organelles.
EUKARYOTICPROKARYOTIC

6. 4. Metabolic Diversity
•Micro-organisms have wide range of energy sources and metabolic pathways:
•Autotrophic-Produce their own food , they are either photosynthetic or chemosynthetic.
•Heterotrophic-Cannot produce their own food, they can either be:
Saprophytes- micro-organisms that feed on dead organic plants and animals.
Parasitic- Micro-organisms that feed on other living organisms.
Mutualistic- Have mutual relationship with other organisms.
•Aerobes- Micro-organisms that require oxygen for respiration.
•Anaerobes-Cannot live without oxygen.
AUTOTROPHIC HETERPTROPHIC
ALGAE Fungi- Bread
Mould

7. 5. INTERACTION WITH OTHER
ORGANISMS
Symbiosis refers to a relationship between
two or mor species that live in direct contact
with each other.
•Parasitism- Symbiotic relationship whereone
organismbenefits while the other one isharmed
e.g. Humans and mosquitos.
•Commensalism- Symbiotic relationship where
one organismbenefits, while the other one is
unaffected e.g. Buffalo and tick bird.
•Mutualism- Symbiotic relationship whereboth
organismsbenefit e.g. Butterfly and flower.
PARASITISM
MUTUALISM
COMMENSALISM

8. FOUR TYPES
OF
MICRO-
ORGANISMS

9. 1. VIRUS
•Viruses are pathogenic.
•They are acellular meaning they do not have a
cell structure.
•The are prokaryotic, meaning they do not have
membrane-bound organelles.
•The cannot respirate, feed or excrete.
•They are obligated intracellular parasite,
meaning to survive and reproduce they need
to be inside the host.
•Outside the host they are dormant.
•They cause diseases such as influenza,
smallpox and HIV.
•Virus that infect bacteria is called a
bacteriophage.

10. 2. Bacteria
•Prokaryotic meaning they do not have membrane bound
organelles.
•Unicellular.
•Some are heterotrophic, some are autotrophic.
•Reproduce by asexual means which include binary fission.
Structure
•Slime capsule- Prevent bacteria from drying out.
•Pilli-Attachment to the host
•Plasma membrane- Movement of oxygen, nutrients and
waste.
•Cell wall- Consist of polysaccharide and it is for support
•Flagellum-Movement
•Nucleoid-Genetic material that is not membrane-bound.
•Some areuseful such as theE.coli which providesvitamin
K to humans.
•Some arepathogenic as they cause diseases such as TB.

11. Mould
Yeast
Mushroom
3. Fungi
•Some are unicellular e.g. Yeast.
•Some are multicellulare.g. Mushroom.
•Eukaryotic(have membrane-bound
organelles).
•Heterotrophicdue to not having chlorophyll.
•Feeding:
•Parasitic: Fungi that feed on leaving
organisms.
•Saprotrophic: Fungi that feed on dead organic
matter.
•Reproduce asexually and sexually by means of
spores.
•Role in the environment is to be decomposers
and return nutrients back to the soil.
•Some are usefule.g.Yeast.
•Some are pathogenicand cause conditions
such as thrush.
EXAMPLES

12. RHIZOPUS
STONOLIFER
EXAMPLE OF A FUNGUS-
MOULD

13. 4. Protista
•No tissue differentiation.
•Eukaryoticmeaning they have membrane
bound nucleus and organelles.
•Can be either multicellularor unicellular.
•Found mainly in water.
•Can either be autotrophic(can make their
own food) or heterotrophic(can not make
their own food).
•Some move using flagellum, some
pseudopodia(false feet).
•Reproduce asexuallyand sexually.
•Some are pathogenicas they cause
diseases such as malaria.
Amoeba
Paramecium
EXAMPLES

14. EUGLENA

16. Nitrogen Cycle
•Higher plants use atmospheric nitrogen asnitrate, therefore
the bacteria converts atmospheric nitrogen into nitrate and
ammonia.
Food Chain
•Many microorganism such as the bacteria and algae are
photosynthetic, meaning they are able to produce their own
food. This provides consumers with carbohydrates.
Balancing carbon dioxide and oxygen
•Photosynthetic microorganisms use carbon dioxide to
photosynthesis and produce oxygen as a product.
Decomposers
•Bacteria and fungi are the main decomposers, they break
down dead organic matter and return the nutrients to the soil,
enriching the soil.

17. REFERENCES FOR SLIDES
A.Karumathil. Introduction to prokaryotes and eukaryotes and differences [PowerPoint slides]. SlideShare.
Introduction to pro and eukaryotes and differences.pptx
KashishSingh43. Microorganism [PowerPoint slides]. SlideShare.
https://www.slideshare.net/slideshow/microorganism-ppt-249943081/249943081#14
MrsSevCTK. Protists science grade 7 [PowerPoint slides]. SlideShare.
https://www.slideshare.net/slideshow/protists-science-grade-7/39900095#1
Microorganisms [PowerPoint slides]-MICROORGANISM.pptxHHJFYIHHHHJDGJHJKKUURTJGJJ | PPTX
Neilfrancisfernandez. General characteristics of microorganisms [PowerPoint slides]. SlideShare.General-
Characteristics-of-Microorganisms.pptx

18. REFERENCES FOR IMAGES/PHOTOGRAPHS
Adobe Stock. (2025). Bacterial cell structures labeled on a bacillus cell with nucleoid DNA and ribosomes [Stock vector]. Adobe Stock.
https://stock.adobe.com/za/images/bacterial-cell-structures-labeled-on-a-bacillus-cell-with-nucleoid-dna-and-ribosomes-external-structures-
include-the-capsule-pili-and-flagellum/366162672
Alchetron. (2024). Amoeba proteus [Photograph]. Alchetron: The free social encyclopedia. Amoeba proteus - Alchetron, The Free Social
Encyclopedia
Andyculpin. (2025). Clusters of brown mushrooms on moss-covered ground [Photograph]. FreeImages. Clusters of brown mushrooms on moss-
covered ground Free Stock Photo | FreeImages
Barlow, N. (2017, December 5). Uranium: A cure for cancer according to new findings from the University of Manchester [Photograph]. About
Manchester. Uranium a cure for Cancer according to new findings from the University of Manchester - About Manchester
Bennett, E. (2024, June 7). E. coli advice issued to public as officials hunt source of major outbreak [Photograph]. BBC News. E. coli advice issued
to public as officials hunt source of major outbreak
Edesignua. (2025). Structure of virus bacteriophage [Stock vector]. Depositphotos. Structure of virus Bacteriophage Stock Vector by ©edesignua
13696096
Petruzzello, M. (2025). Meet the microbes: 5 tiny protozoans and algae [Photograph]. In Britannica. 5 Tiny Protozoans and Algae | Britannica
Rachel. (2025). Euglena under a microscope – Anatomy, reproduction & facts [Photograph]. Rs’ Science. Euglena under a microscope - anatomy,
reproduction & facts - Rs' Science
Reynolds, L. (2022). How does mold grow on bread? Sciencing. How Does Mold Grow On Bread?
Roth, D. (2017, February 22). Teachers, how to avoid becoming stale. LinkedIn. (20) Teachers, How to Avoid Becoming Stale | LinkedIn

19. Science Facts. (2025). Amoeba: Parts and structure with characteristics and diagram [Photograph]. ScienceFacts.net.
https://www.sciencefacts.net/amoeba-definition-structure-characteristics-diagram
Selina. (2024, December 1). Yeast facts: 11 facts about yeast, the versatile microorganism. FACT.net. 11 Facts About Yeast The
Versatile Micoroorganism- Facts.net
Shutterstock. (2025). Coloring page with bacterial cell structure: Prokaryotic cell with nucleoid, flagellum, plasmid and other
organelles [Stock vector]. Coloring Page Bacterial Cell Structure Prokaryotic Stock Vector (Royalty Free) 2098536667 |
Shutterstock
Stephens, O. (2022, April 12). Hydroponic mushrooms: An ultimate growing guide. The Hydroponic Planet. Hydroponic Mushrooms:
Ultimate Growing Guide - The Hydroponics Planet
StudiousGuy. (2025). Rhizopus characteristics & uses [Photograph]. StudiousGuy. Rhizopus Characteristics & Uses –
StudiousGuy
The Editors of Encyclopedia Britannica. (2025). Microbiology summary. In Britannica. microbiology summary | Britannica WorldAtlas.
(2025). What is the ecological importance of algae? WorldAtlas. What Is The Ecological Importance Of Algae? - WorldAtlas

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