PROTOZOA Flashcards
Dates to 3.5 billion years ago
First evidence of life
Origin of complex eukaryote cells
Cellular Symbiosis
First cells were
bacteria-like
Modification of engulfed
prokaryote into an organelle:
Primary endosymbiosis
Aerobic bacteria engulfed by
bacteria
May have become
______ found in most
modern eukaryotic cells
mitochondria
Engulfed photosynthetic
bacteria evolved into
chloroplasts
Descendants in green algae lineage gave rise to
multicellular plants
One eukaryotic cell engulfed another eukaryotic cell
Secondary endosymbiosis
how did the emergence of Eukaryotes happen?
Other groups apparently originated by Secondary endosymbiosis
Latter became transformed into an organelle
lack cell wall
one motile stage in the life cycle
most ingest their food
Carry on all life activities within a single-cell
Can survive only within narrow environmental ranges
Very important ecologically
Protozoa
there are at least * amount* species of protozoa are symbiotic in or on other plants on animals
10,000
Kingdom Protista members
Plant-like protist (algae)
Animal-like protists (protozoans)
Fungus like protist
photosynthetic autotrophs
algae
plant-like protists
heterotrophs
protozoa
Animal-like protist
heterotroph
molds
fungi-like protist
Plant-like protist examples
unicellular
euglenophyta
Chrysophyta
pyrrophyta
multicellular
chlorophyta
Phaeophyta
Rhodophyta
Examples of Animal-like protists
Sarcodina - amoeba
Ciliophora- paramecium
Zoomastigophora - tripanosome
sporozoa - plasmodium
Fungus time protist examples
myxomycota-slime molds
oomycota-water molds
Once considered one phylum
Recently shown that there are at least seven or more phyla
May be more than 60 exclusive eukaryotic clades
Now used informally without implying phyletic relationship
Protozoa
Nutrition in Protozoans
Autotrophs
Heterotrophs
Mixotrophs
Nutrition in Protozoans
contain chloroplasts
Autotrophs
Nutrition in Protozoans
absorb organic molecules or ingest larger food particles
Phagocytosis
Heterotrophs
Nutrition in Protozoans
combine photosynthesis and heterotrophic nutrition
Mixotrophs
Protozoans Occur in Diverse Habitats, where?
Freshwater and marine
Require moisture
Diverse relationships of protozoans
Mutualistic Commensalistic Parasitic
Protists have three main methods of locomotion
have one or two long flagella that they can whip around and propel themselves through the water
cillia for both feeding and locomotion
Others use ameboid movement to get around
A pseudopod is extended forward,
followed by the rest of the organism
ameboid movement
Cilia and flagella share an internal structure of the
extending beyond the cell
consisting of 9 pairs of microtubules surrounding a central pair
axoneme
Inside the cell, the
consists of 9 triplets of microtubules just like centrioles.
kinetosome
are extensions of the cell cytoplasm used for locomotion.
Pseudopodia
Large blunt extensions of the cell body
Contains both endoplasm and ectoplasm
Lobopodia
Thin extensions Containing only ectoplasm
Filopodia
Repeatedly rejoin to form a netlike mesh
Reticulopodia
Long thin pseudopodia
Support by axial rods of microtubules
Axopodia
Functional Components of Protozoan cells
Nucleus
Mitochondria
Golgi
Plastids
Extrusomes
Nutrition intake methods in Protozoans
Holozoic feeders, or phagotrophs
pinocytosis
ingest particles of food
Holozoic feeders, or phagotrophs
the membrane-bound vesicle containing the food.
fuse with lysosomes containing digestive enzymes.
Food vacuole
the site of phagocytosis is a definite mouth structure
cytosome
Saprozoic feeding may be by
or by transport of solutes across the cell membrane.
pinocytosis
ingestion of soluble food
Saprozoic feeding
Organelle used for Excretion and osmoregulation
Contractile vacuoles
fill with fluid and then expel the fluid outside the cell
More common in freshwater
species.
Contractile vacuoles