Introduction to Kingdom Protista Flashcards

Introduction to Kingdom Protista

Overview

• Kingdom Protista is a diverse group of eukaryotic organisms. It is often nicknamed the "Junk Drawer Kingdom" because it contains 16 phyla and is not organized in detail.

Key Figures

• Ernest Haeckel: Credited with first using the term "Protista" in 1886.

Endosymbiotic Theory

• The endosymbiotic theory explains the origin of eukaryotic organisms.
• Summary of the Theory:
  • A larger cell engulfs a smaller cell.
  • Aerobic Bacteria: Engulfed by a larger cell and evolves into mitochondria.
  • Photosynthetic Bacteria: Engulfed by a larger cell and evolves into chloroplasts.

Classification of Protists

• Currently, the best method for classifying protists is according to how they obtain nutrition. This puts protists into three major categories:
  • Plant-Like Protists
    • Autotrophic (produce their own food).
    • Ancestors of plants today.
  • Animal-Like Protists
    • Heterotrophic (consume other organisms for food).
    • Ancestors of multicellular animals.
  • Fungus-Like Protists
    • Decomposers.
    • Ancestors of modern-day fungi.

Protist Examples and Structures

Alga

• Plant-like protist.
• Autotrophic.
• Cell Structures (as labeled):
  • Chloroplast
  • Cytoplasm
  • Nucleus
  • Pellicle

Amoeba

• Animal-like protist.
• Heterotrophic.
• Cell Structures (as labeled):
  • Nucleus
  • Contractive vacuole
  • Ectoplasm
  • Endoplasm
  • Pseudopods
  • Food vacuole

Paramecium

• Animal-like protist.
• Heterotrophic.
• Cell Structures (as labeled):
  • Macronucleus
  • Micronucleus
  • Cell membrane
  • Contractile vacuole
  • Oral groove
  • Gullet
  • Cilia

Protist Cell Structure Functions

• Contractile Vacuole (all): Removes excess water.
• Flagella (Euglena): Helps to move.
• Eyespot (Euglena): Detects light.
• Chloroplast (Euglena): Traps sunlight for photosynthesis.
• Pseudopod (Amoeba): "False foot" used to wrap around and ingest food particles.
• Food Vacuole (Amoeba/Paramecium): Stores food (contains lysosomes).
• Cilia (Paramecium): Used for movement.
• Pellicle (Euglena/Paramecium): Tough outer layer.

Classification Flexibility

• The way organisms are classified is not set in stone. Scientists predict there may be 10-12 more kingdoms in the coming years.