Microbiology Unit 1 Quiz

Study Notes

Microbiology studies microorganisms, a diverse group of microscopic organisms including bacteria, archaea, viruses, fungi, prions, protozoa, and algae.
Microorganisms are defined as organisms too small to be seen clearly with the naked eye, generally 1 millimeter or less in diameter.
This field has two main themes: understanding microbial life and applying this knowledge for human and environmental benefits.
Microbiology explores fundamental life processes and has led to breakthroughs in medicine, agriculture, and industry.

Prokaryotes are simpler, smaller cells including Bacteria and Archaea; eukaryotes are larger, more complex cells with membrane-bound organelles.
Eukaryotic microorganisms include algae, protozoa, protists, and fungi, which have various specialized functions within the cell.

Organisms have been classified into kingdoms based on various criteria, evolving from the two-kingdom system proposed by Linnaeus to a five-kingdom system by R.H. Whittaker.
Criteria for classification include:
- Cell structure complexity: prokaryotic vs eukaryotic
- Organism complexity: unicellular vs multicellular
- Mode of nutrition: autotrophs (plants) vs heterotrophs (fungi and animals)
- Lifestyle roles: producers, consumers, decomposers
- Phylogenetic relationships: the evolutionary lineage connecting prokaryotes and eukaryotes

Historically, microorganisms were thought to arise spontaneously from non-living materials (spontaneous generation).
Key historical figures include:
- Aristotle promoted spontaneous generation theory.
- Roger Bacon linked diseases to invisible "seeds" or "germs".
- Antony Van Leeuwenhoek, known as the Father of Bacteriology, first observed microorganisms (termed "Animalcules") using a microscope in the 17th century.
- The term "microbe" was introduced by Sedillot in 1878.

Francesco Redi challenged the spontaneous generation theory by demonstrating that maggots do not originate from decaying meat when covered.
John Needham, contrastingly, supported spontaneous generation, claiming that tiny organisms arose spontaneously in broth.