Microorganisms Definition and Characteristics

Study Notes

Microorganisms are tiny living organisms that are too small to be seen with the naked eye
They are typically measured in micrometers (μm) or nanometers (nm)
Microorganisms can be found almost everywhere on Earth, including in soil, water, air, and the human body

Bacteria: prokaryotic cells, no nucleus or membrane-bound organelles
- Examples: E. coli, Staphylococcus aureus, Bacillus subtilis
Viruses: not considered living cells, consist of genetic material surrounded by a protein coat
- Examples: Influenza, HIV, Ebola
Fungi: eukaryotic cells, have a nucleus and membrane-bound organelles
- Examples: Yeast, Mold, Mushrooms
Protists: eukaryotic cells, do not fit into any other category
- Examples: Amoeba, Paramecium, Giardia

Symbiosis: living together in a close, often beneficial relationship
- Examples: gut microbiome, coral-algae symbiosis
Antagonism: competing with each other for resources
- Examples: antibiotic production, competition for nutrients
Mutualism: both organisms benefit from the interaction
- Examples: mycorrhizal fungi, lichen formation

Microorganisms are tiny living organisms that are too small to be seen with the naked eye, typically measured in micrometers (μm) or nanometers (nm).
They can be found almost everywhere on Earth, including in soil, water, air, and the human body.

Bacteria: prokaryotic cells with no nucleus or membrane-bound organelles, examples include E. coli, Staphylococcus aureus, and Bacillus subtilis.
Viruses: not considered living cells, consist of genetic material surrounded by a protein coat, examples include Influenza, HIV, and Ebola.
Fungi: eukaryotic cells with a nucleus and membrane-bound organelles, examples include Yeast, Mold, and Mushrooms.
Protists: eukaryotic cells that don't fit into any other category, examples include Amoeba, Paramecium, and Giardia.

Symbiosis: living together in a close, often beneficial relationship, examples include gut microbiome and coral-algae symbiosis.
Antagonism: competing with each other for resources, examples include antibiotic production and competition for nutrients.
Mutualism: both organisms benefit from the interaction, examples include mycorrhizal fungi and lichen formation.