Protista and Fungi Notes

Eukaryotes - Kingdom Protista and Kingdom Fungi

Eukaryotic Cell Characteristics

  • Nucleus: Eukaryotic cells have a nucleus.

  • Membrane-bound organelles: Eukaryotic cells contain membrane-bound organelles.

  • Size: Eukaryotic cells are generally larger than prokaryotic cells.

Kingdoms within Domain Eukarya

  • Protista

  • Fungi

  • Plantae

  • Animalia

Endosymbiotic Theory

  • Summary: A larger prokaryote engulfed a smaller prokaryote, living symbiotically and dividing as one. The smaller prokaryote eventually became an organelle.

Kingdom Protista

General Characteristics

  • Considered the first eukaryotic organisms.

  • Reproduction: Asexual and sexual reproduction methods are observed.

  • Cellularity: Unicellular or multicellular organisms.

  • Nutrition: Autotrophic or heterotrophic.

Nickname: "Junk Drawer Kingdom"

  • Appropriate because some organisms don't fit neatly into the other three kingdoms.

Classification Based on Nutrition

  • Plant-like protists (autotrophic)

  • Animal-like protists (heterotrophic)

  • Fungus-like protists (saprotrophic)

Animal-Like Protists

Protozoans

  • Another name for animal-like protists, meaning "first animal".

  • Distinguishing characteristic: Heterotrophic nutrition.

  • Movement: Amoebas use pseudopods, while paramecia use cilia.

Plant-Like Protists

Algae

  • Plant-like characteristics: Autotrophic photosynthesizers that produce their own food using energy from the sun.

Algal Bloom (Red Tide)

  • Cause: Plentiful food and favorable conditions leading to rapid reproduction of dinoflagellates.

  • Dangers: Depletes nutrients and oxygen, causing marine organisms to suffocate.

Fungus-Like Protists

Distinguishing Characteristics

  • Saprotrophic (decomposers).

  • Use spores for reproduction.

  • Difference from true fungi: Cell walls are made of cellulose, not chitin.

Examples

  • Slime molds

  • Water molds

  • Downy mildew

Kingdom Fungi

Defining Features

  • Eukaryotic.

  • Heterotrophic.

  • Contain hyphae.

  • Fungal cell walls are made of chitin.

  • Multicellular (except for yeasts, which are unicellular).

Hyphae

  • Threadlike filaments that make up the body of a fungus.

Mycelium

  • Net-like mass of branching hyphae, typically found underground.

Advantage of Filamentous Body

  • Increases surface area for nutrient absorption.

Fruiting Body

  • The reproductive structure of a fungus seen above ground.

Energy Acquisition

  • Fungi digest then ingest

  • Type of heterotroph:

    • Saprophytes: Feeds on dead organism or organic wastes.

    • Parasites: Absorbs nutrients from living cells. Example: Athlete's Foot, Ringworm.

    • Mutualistic Fungi: Mycorrhizae shows close relationship with other plant. Example: roots of soybean species.

Fungal Reproduction

Asexual Reproduction

  • Budding: Yeast cells develop new cells that pinch off from the parent cell.

  • Fragmentation: Mycelium is physically broken apart and begins to grow.

  • Spore production: Spores are used in both asexual and sexual life cycles.

Spores

  • Key to sexual reproduction.

  • Adaptations for survival: Small, lightweight, and have waterproof cell walls.

Fungal Symbiotic Relationships

Lichens

  • Mutualistic relationship between fungi and algae.

  • Benefits:

    • Fungi provide a dense web for algae to grow.

    • Algae provides usable sugars to Fungi.

    • Lichens are sensitive to environmental change

  • Fungi are very resilient

Mycorrhizae

  • Fungi that wrap around the roots of certain plants.

  • Benefits:

    • Fungus absorbs and concentrates minerals for the plant.

    • Hyphae increase surface area of the root system.

Benefits of Fungi

  • Bioremediation.

  • Medicines.

  • Foods.

Harmful Fungi

  • Destruction of plants and crops.

  • Parasitic fungi causing infections.