Classification Lecture Notes
Review of Classification One
- Definition of Classification: Orderly grouping of living organisms based on shared characteristics.
- Reasons for Classification:
- To identify organisms and group them for future reference.
- To separate organisms with different features, organizing information to avoid confusion.
Taxonomic Units of Classification
- Kingdom - Highest and largest taxonomic unit.
- Phylum or Division
- Class
- Order
- Family
- Genus
- Species - Least taxonomic unit.
Five Kingdoms in Biology
- Kingdom Monera
- Kingdom Protista
- Kingdom Fungi
- Kingdom Plantae (Note: spelling)
- Kingdom Animalia
- Focus on Kingdom Animalia: Includes humans.
- Study two phyla in Kingdom Animalia: Phylum Arthropoda and Phylum Chordata
Focus on Phylum Arthropoda
- Characteristics of Animals:
- Multicellular
- Lack cell walls
- General Characteristics of Phylum Arthropoda:
- Jointed appendages
- Hardened exoskeleton made of chitin
- Segmented bodies
- Bilateral symmetry
- Sexual reproduction
- Open circulatory system
Classes Under Phylum Arthropoda
- Class Arachnida
- Examples: Scorpions, ticks, spiders
- Characteristics:
- Two body parts: cephalothorax and abdomen
- Four pairs of legs (eight walking legs)
- Lack antenna
- Gas exchange through book lungs and tracheal system
- Carnivorous, use poison to paralyze prey
- Class Crustacea
- Examples: Crayfish, crabs, lobsters
- Characteristics:
- Cephalothorax covered by a carapace
- Two pairs of antenna
- Pair of compound eyes
- Five or more pairs of limbs
- Class Chilopoda
- Example: Centipedes
- Characteristics:
- Two body parts: head and trunk
- One pair of legs per segment
- One pair of long antenna
- Poisonous claws
- Class Diplopoda
- Example: Millipedes
- Characteristics:
- Cylindrical body
- Two pairs of legs per segment
- Short antenna
- Three body parts: head, thorax, trunk
- Class Insecta
- Examples: Housefly, ants, bees
- Characteristics:
- Three body parts: head, thorax, abdomen
- One pair of antenna
- Compound and simple eyes
- One or two pairs of wings
- Gas exchange through tracheal system
- Waterproof exoskeleton
Summary and Exam Tips
- Differentiate Class Chilopoda and Diplopoda:
- Chilopoda (Centipedes): Two body parts, one pair of legs per segment, long antenna, poisonous claws.
- Diplopoda (Millipedes): Three body parts, two pairs of legs per segment, short antenna.
- Phylum Arthropoda Special Features: Segmented body, jointed appendages, exoskeleton made of chitin.
Homework/Review Questions
- List three differences between Class Chilopoda and Diplopoda.
- List three distinguishing characteristics of Class Arachnida.
This concludes the lecture on Classification Two focusing on Phylum Arthropoda. Enjoy your holiday!