Chapter 18: Protists VirusMoneraProtista

Taxonomic thinking Animals Plants Fungi Protists Monera

EUKARYA BACTERIA ARCHAEA Protists Plants Fungi Animals Phylogenetic Thinking

ProkaryotesProkaryotes vs Eukaryotes Eukaryotes ProkaryotesEukaryotes

Prokaryotes Prokaryotes Kingdoms: Monera (bacteria) Kingdoms: Monera (bacteria) cell membrane and cell wall. cell membrane and cell wall. Prokaryotic cells lack nucleus and membrane bound "organelles,“ Prokaryotic cells lack nucleus and membrane bound "organelles,“ Some have flagella for locomotion or hair like pili for adhesion. Some have flagella for locomotion or hair like pili for adhesion. Cells: multiple shapes: cocci (round), baccilli (rods), and spirilla (helical cells). Cells: multiple shapes: cocci (round), baccilli (rods), and spirilla (helical cells). Note: prokaryotes will not have microtubules in flagella Note: prokaryotes will not have microtubules in flagella BACK

Eukaryotes Eukaryotes Cells have nuclei and membrane-bound organelles Cells have nuclei and membrane-bound organelles

What are Protists?

Greek word meaning “first” Greek word meaning “first” First kingdom of eukaryotes First kingdom of eukaryotes Unicellular Unicellular Nuclei Nuclei Organelles Organelles Reproduce by mitosis Reproduce by mitosis Multiple chromosomes Multiple chromosomes Protists often have a very complicated internal structure: a single cell must do all the functions that we have many different cell types to do. Protists often have a very complicated internal structure: a single cell must do all the functions that we have many different cell types to do. Increasing in diversity

Surface waters teem with microscopic protists In some near- shore areas, gigantic protists form underwater forests Protists are particularly abundant in tidal habitats All protists live in water, or moist soil, or moist interiors of other organisms

Classification 115,000 species 115,000 species Major debate regarding how they should be classified Major debate regarding how they should be classified “animal-like” = zooplankton or protozoans “animal-like” = zooplankton or protozoans “plant-like” = phytoplankton “plant-like” = phytoplankton

Increasing diversity Protists share characteristics with more then one multicellular kingdom Protists share characteristics with more then one multicellular kingdom - plant-like -fungus-like -animal-like forms

Animal-like Protists

Plants-like Protists

Fungus-like Protists (slime molds)

Protists exhibit wide variation in morphology, size, and nutritional strategies

Protists are divided into groups largely based on locomotion 1) Sarcodines 1) Sarcodines –Blob-like asymmetrical –Assume infinite variety of shapes –Ex. Amoebae 2) Flagellates 2) Flagellates –Ex. Euglena 3) Ciliates 3) Ciliates –Ex. Paramecium 4) Sporozoans 4) Sporozoans –Have no organs for locomotion in adult form –Many are parasitic

BACTERIA ARCHAEA Parabasalids Diplomonads Kinetoplastids Euglenids Amoebae Slime molds Ciliates Apicomplexa Dinoflagellates Oomycetes Diatoms Brown algae Red algae Green algae Land plants Fungi Animals PROTISTS Figure 27.1

We will observe the following four: Ciliates Ciliates – 1) Paramecium caudatum – 2) Stentor coeruleus Sarcodines Sarcodines – 3) Amoeba proteus Flagellates Flagellates – 4) Euglena gracili

Paramecium Paramecium Live in FRESH water Live in FRESH water Osmosis causes water to move into the paramecium Osmosis causes water to move into the paramecium Contractile vacuole collects the extra water so that the paramecium doesn’t lyse Contractile vacuole collects the extra water so that the paramecium doesn’t lyse Covered in cilia used for locomotion and for directing food into the oral cavity Covered in cilia used for locomotion and for directing food into the oral cavity Most are free-living (not parasites) Most are free-living (not parasites)

Amoeba Sizeable amount of cytoplasm Sizeable amount of cytoplasm Cytoplasmic streaming pushes on the cell membrane resembling arms Cytoplasmic streaming pushes on the cell membrane resembling arms A clear nucleus A clear nucleus False foot: pseudopods to move and capture prey False foot: pseudopods to move and capture prey Feeding: endocytosis: surround food; creates a food vacuole. Feeding: endocytosis: surround food; creates a food vacuole. Ameoba reproduce by binary fission Ameoba reproduce by binary fission

Euglena Plant-like Plant-like Long flagellum excellent swimmers Long flagellum excellent swimmers A red-spot (photoreceptor) helps euglena detect sunlight so it’s chloroplasts can make glucose using photosynthesis A red-spot (photoreceptor) helps euglena detect sunlight so it’s chloroplasts can make glucose using photosynthesis

Stentor coeruleus (S.coeruleus) trumpet-shaped or cylindrical; highly contractile trumpet-shaped or cylindrical; highly contractile contractile vacuole anterior-left; fresh water contractile vacuole anterior-left; fresh water