Lecture Notes: Classification and Taxonomy

Introduction

• Lecture introduction includes a personal anecdote about cool animals and a 7th-grade memory about hydra.
• Hydra characteristics:
  • Small animals, a few millimeters in length.
  • Live in freshwater.
  • Predatory and reproduce by budding.

Classification and Taxonomy

• Classification: Process of naming and categorizing species.
• Carl Linnaeus credited for developing formal classification.
• Historical context: 18th-century lack of cellular and genetic knowledge.
• Classification evolves with DNA and genetic relationship discoveries.

Hierarchy System Mnemonic

• Example mnemonic: "Dear King Paramecium Cares Only For Green Spirulina"

Domains

• Three Domains of Life:
  1. Bacteria:
     • Prokaryotes with diverse roles (e.g., disease, digestion, decomposition, nitrogen fixation).
  2. Archaea:
     • Prokaryotes with DNA and structure different from bacteria.
     • Extremophiles, e.g., halophiles, methanogens, thermophiles.
  3. Eukarya:
     • Eukaryotes with shared characteristics discussed previously.

Kingdoms

• Eukaryotic Kingdoms:
  • Organization often changes; not universally agreed upon.
  • Examples include 5 and 6 kingdom systems.

Protista

• Highly diverse group, potential for subdivision.
• Includes animal-like, plant-like, and fungi-like protists.
• Autotrophs and heterotrophs, mostly unicellular, some multicellular.

Fungi

• Heterotrophs (example: athlete’s foot).
• Usually multicellular, sometimes unicellular.
• Cell walls made of chitin.

Plantae

• Autotrophs, including carnivorous plants.
• Multicellular, cell walls of cellulose.

Animalia

• Mostly multicellular and heterotrophic.
• Kingdom includes hydra and other animals.

Hierarchy Levels Below Kingdom

• Phylum, Class, Order, Family, Genus, Species:
  • From more inclusive to least inclusive.
• Species Name:
  • Scientific naming system by Carl Linnaeus: binomial nomenclature.
  • Consists of Genus (capitalized, italicized) and Specific epithet (lowercase, italicized).

Importance of Scientific Names

• Avoids confusion of common names across different locations.
• Example: Mountain lion also known as puma, cougar, or Texas Panther.
• Scientific names provide consistency and universal recognition.

Conclusion

• End with a reminder to "stay curious."

Social Media

• Follow @AmoebaSisters on Twitter and Facebook.