(1) Protozoa Flashcards
Anthony van Leeuwenhoek 1674
First person to see protista
Protista
a kingdom; but NOT bacteria, fungi, plant, OR animal
Protozoa
once a phylum in the animal kingdom
-Animal-like Protista
General Characteristics (Protozoa)
Unicellular eukaryote
Locomotion (Protozoa)
Pseudopod
Cilia and Flagella
1. Paired microtubules
2. cilia=shorter, flagellum=longer
Nutrition (Protozoa)
- Phagotrophs: solid food
- Osmotrophs: liquid food
Asexual Reproduction (Protozoa)
-Budding: fission of smaller cell from larger
-Binary Fission: fission into two equal-sized cells
-Schizogony (split): nucleus divides several times
Sexual Reproduction (Protozoa)
- Conjugation
-two cell pair, exchange gametic nuclei
-genetic variation increases, vigor is restored
Encystment (Protozoa)
hardcover forms and metabolism slows
-dormancy lasts until harsh conditions pass
Types of Pseudopodia
- Lobopodia: broad lobe
- reticulopodia: branch and rejoin
- Axopodia and Filopodia: thin, radiate out
Phylum Ameobozoa
Typical amebas
-heterotrophs (phagocytosis)
-some have tests (shells)
Phylum Foranifera
foraminifera- calcium test (shell)
-reticulopodia catch prey on ocean bottom (benthic)
Phylum Radiolaria
Radiolarian- silica test (shell)
-axopodia or filopodia catch prey as they float in the ocean (pelagic)
Phylum Stramenopiles
axopodia prey as they float in freshwater
Phytoflagellates
-have chlorophyll
- referred as algae
- sometimes heterotrophic or parasitic
Zooflagellates
-colorless heterotrophs (animal-like)
-many are symbionts, some are also parasites
Phylum Virdiplantae
-phytoflagellates
Example: Volvox - multicellular colony, autotrophic
Phylum Euglenozoa
-zooflagellates
Example:
-Euglena, autotroph, and heterotroph when light-limited
-Trypanosoma - parasitic heterotroph, african sleeping sickness, tsetse fly
Phylum Dinoflagellata
two flagella at right angles
-dino: “whirling”
-some are phytoflagellates
Plankton (Phylum Dinoflagellata)
small passively floating animals, plants, and protistans in water; base of aquatic food chain
Zooxanthellae (Phylum Dinoflagellata)
term for dinoflagellates that are considered algae and that are also ENDOSYMBIONTS inside many jellyfish, corals, and molluscs; a MUTUALISTIC relationship
Phylum Diplomonada
flagella: mostly commensal in vertebrate intestine
Symptoms Giardia Lambia (Phylum Diplomonada)
causes diarrhea in a number of mammals (humans, beaver)
Phylum Ciliophora
- Multinuclear
-macronucleous: metabolism, growth
-micronucleous: divide/exchange in conjunction - trichocysts/toxicysts: defensive thread or toxin expelled to paralyze prey
Paramecium (Phylum Ciliophora)
- freshwater osmotroph
- Oral groove, contractile vacuoles
- Binary fission (asexual) and conjuction (sexual)
Endosymbionts (Phylum Ciliophora)
commensal and parasitic
Example: Ick
Suctorians (Phylum Ciliophora)
- young swim with cilia
- adults become sessile on stalk, lose cilia, develop paralyzing tentacles
Phylum Apicomplexa
- all endoparasites
- Apical complex aids infection
Toxoplasma (Phylum Apicomplexa)
cats a main host
congenital (born with) toxoplasmosis: 2% of US mental retardation
Plasmadium (Phylum Apicomplexa)
Malaria
1. primary host:
mosquito -> gametes -> zygote -> sporozoites -> salivary glands -> humans
- Secondary host:
Human -> sporozoites -> liver -> merozoites -> rbc bursting -> toxins=chills/fever -> immature gambetes picked up by mosquito
