Kingdom Protista and Protozoa

• Objectives are describing, classifying, and differentiating various characteristics
• Classifying given species into a taxon for Kingdom Fungi and Protists

Kingdom Protista

• Eukaryotes with a nucleus
• Many unicellular organisms exist, and numerous colonial and multicellular groups
• Protists prefer aquatic and moist environments
• Exhibit all types of nutrition, and can be free-living or parasitic
• Reproduce asexually, with some undergoing sexual reproduction or both
• Are a collection of 200,000+ species of eukaryotes that do not fit into fungi, plants or animals
• Classifiable into animal-like, plant-like and fungus-like

Protozoa (Animal-like Protists)

• Also known as protozoa, or "primitive animal"
• All are unicellular and heterotrophic
• Feed by ingestion
• Classified based on mode of movement
• Use cilia for feeding and locomotion, acting like oars, e.g. Paramecium
• Sarcodine use pseudopods for feeding and locomotion via phagocytosis, e.g. Amoebas
• Entamoeba histolytica causes amoebic dysentery
• Zooflagellates move by beating flagella; typically live in host organisms
• Ex: Giardia lamblia causes diarrhea, Trypanosoma brucei causes African sleeping sickness, which is caused when the tsetse fly bites and spreads it
• Trichonympha digests the cellulose in wood, supporting termite nutrition

Sporozoans

• Unicellular protists and parasites which produce spores
• Earlier stage shows some movement
• Do not possess locomotor organelles in later stage
• Plasmodium vivax causes malaria and lives inside Anopheles mosquitoes

Algae (Plant-like Protists)

• Labeled "plant-like" because to their capability to photosynthesize, usually unicellular
• Classified based on cell structures and pigment color instead of cell walls like protozoa
• Live in soil, bark, fresh water, or salt water
• Diatoms are algae that have a unique glass-like wall with silicon dioxide
• The walls are embedded in matrix, creating lid-like structure
• Dinoflagellates have cells protected by thick cellulose plates resembling helmets or medieval armor
• They form the basis aquatic food chains
• Euglenoid exhibits behavior of both plants and animals.
• Photosynthetic, yet without a cell wall
• They can absorb dissolved nutrients or capture prey such as smaller euglenoids
• Mostly found in freshwater and some have flagella
• Green algae are closest relatives of plants; both have cell walls
• They have Chlorophyll as a primary pigment as well as carbohydrates as food storage, giving it green color
• Red algae is multicellular and has a reddish color caused by phycoerythrin
• Photosynthetic pigment that masks green chlorophyll and allows absorption of green, blue and violet light, allowing them to thrive deeper in the sea
• Golden algae's color is due to carotenoids, and may be unicellular/colonial mixotrophs
• Golden Algae absorb dissolved compounds or ingest food particles through phagocytosis
• Brown algae are commonly called kelps
• Have plant-like appearance and are multicellular.
• Spherical bodies called bladders float algal near the surface of the water for photosynthesis
• Coloration is defined by carotenoids in its plastids

Classification of Fungus-like Protists

• Are heterotrophic and possess cell walls; can be saprophytes or parasites
• Produce spores like fungi
• Slime molds consist of
  • Slime molds live as a large mass of plasmodium with multiple nuclei in a single cytoplasm
  • Thrive in moist soil and decay on plants
• The slime extends through moist soil, leaf mulch, or rotting logs and engulfing food particles
• Cellular Slime Molds are called so as unlike plasmodial ones, they function either as individual cells or an aggregate
• Solitary cells function individually at feeding stage, but when food levels are low, cells turn into slug aggregate
• Water molds are a group of filamentous Protists physically resembling fungi
• Resemblance to fungi from a historical preference for watery environments

Kingdom Fungi

• Decay is crucial for organic matter recycling within ecosystem
• Decaying splits molecules into nutrients
• One major player in these processes is Kingdom Fungi

General Fungi Characteristics

• Eukaryotic with cell walls made of chitin; non-vascular
• Chloroplasts are non-existent in fungi
• Can be either unicellular or multicellular (filamentous)
• Heterotrophic behavior to obtain nutrients via secreting enzymes for digestion and absorption
• Can sexually reproduce in spores or fuse hyphae to do so

Fungi Structures

• Unicellular fungi=yeasts, ex: Saccharomyces cerevisiae, used to bake bread and brew beer
• Multi-cellular fungi develop filaments called hyphae to increase the surface area for nutrient absorption.
• Branching filaments Hyphae consist of one or more cells surrounded by a tubular cell wall
• The vegetative structure is an intertwined mass of Hyphae known as Mycelium

Reproduction Structures

• Fungi create spores
• Asexual reproduction involves spores drifting to reproduction
• Sexual reproduction involves fusion of hyphae

Chytridiomycota

• Fungi belonging to this taxon includes members called chytrids
• They reproduce via motile, flagellated spores called zoospores
• Largely aquatic, using water to swim
• Chytrids release haploid flagellated spores into environment
• Under favorable conditions, spores germinate and produce new chytrids, which sometimes reproduce sexually

Zygomycota

• Popluarly referred to as molds
• Fast-growing, used to rot foods like bread, sweet potato, and strawberry
• Bread mold consists of mycelia penetrating bread, stalks sporangiophores

Glomeromycota

• Newly discovered group of fungi
• Establish symbiotic relations with other plants via arbuscular mycorrhizae
• Help provide root minerals/nutrients, contributing to overall absorption

Phylum Ascomycota

• Fungi characterized by the presence of saclike structures called asci
• Asci contain reproductive ascospores
• Most ascomycetes develop "ascocarps" fruiting bodies during their sexual phase
• Ascocarps contain spore-forming asci, leading to asexual reproduction
• Creates an enormous number of spores

Basidiomycota

• Known as "club fungi".
• Feature distinguishing this class is is the existence of a club shaped structures called Basidia
• Reproductive spores contained within
• The visible reproductive structure here groupis is the Basidiocarp which are fungi like mushrooms / puffballs
• Certain kinds decomposing lignin for energy and breaking down wood

Learn about Kingdom Protista, eukaryotes with diverse characteristics and habits, including animal-like protozoa, unicellular heterotrophs that feed by ingestion. Explore their classification based on movement, such as cilia (Paramecium) and pseudopods (Amoebas). Discover the fascinating world of Protista and Protozoa.