19.1 Diversity of Protists
KEY CONCEPT
Kingdom Protista is the most diverse of all the kingdoms.
19.1 Diversity of Protists
Protists can be animal-like, plantlike, or funguslike.
• Protists are eukaryotes (meaning they have a nucleus and
other organelles) that are not animals, plants, or fungi.
19.1 Diversity of Protists
• Animal-like protists consume other organisms.
– They are called heterotrophs
– They are often predators.
19.1 Diversity of Protists
• Plantlike protists are photosynthetic.
– single-celled, colonial, or multicellular
– no roots, stems, or leaves
Diatoms
Kelp
19.1 Diversity of Protists
• Funguslike protists decompose dead organisms.
– heterotrophs
– can move, whereas fungi cannot
19.1 Diversity of Protists
Protists are difficult to classify.
• Protista is often called one
kingdom
• But it may be broken down into
more than one after scientists
learn more about them.
19.1 Diversity of Protists
• Protist classification will likely change.
– Some protists are not closely related.
– Molecular evidence supports reclassification.
Know
this!!
19.2 Animal-like Protists
KEY CONCEPT
Animal-like protists are single-celled heterotrophs
that can move.
19.2 Animal-like Protists
Animal-like protists move in various ways.
• Animal-like protists are often called protozoa.
macronucleus
contractile vacuole
food vacuole
oral groove
micronucleus
cilia
19.2 Animal-like Protists
• Protozoa with flagella are zooflagellates.
– flagella help zooflagellates swim
– more than 2000 zooflagellates
19.2 Animal-like Protists
• Some protists move with pseudopods.
– change shape as they move
– amoebas
http://www.youtube.com/watch?v=ZmWIMxW-GkQ&feature=related
19.2 Animal-like Protists
• Some protists move with pseudopods.
– change shape as they move
– amoebas and…
Forams
19.2 Animal-like Protists
• Some protozoa move with cilia.
– cilia help protists swim and capture food
– more than 8000 ciliates
macronucleus
contractile vacuole
food vacuole
oral groove
micronucleus
cilia
19.2 Animal-like Protists
Some animal-like protists cause disease.
• Protists cause some wellhuman liver
known infectious diseases.
• Malaria is caused by
Plasmodium and spread by
mosquitoes.
• Sleeping sickness is caused
by Trypanosoma and spread
by flies.
• A giardia infection is caused
by Giardia and spread
through water.
sporozoites
liver cells
developed
parasites
red blood
cells
Malaria Infection
19.3 Plantlike Protists
KEY CONCEPT
Algae are plantlike protists.
19.3 Plantlike Protists
Plantlike protists can be single-celled or multicellular.
• Photosynthetic plantlike protists are called
algae.
colony
Volvox
daughter colony
19.3 Plantlike Protists
Protists
(Diatoms)
Do photosynthesis, but are protected by a silica (glass) shell
19.3 Plantlike Protists
• Euglenoids are a large group of plantlike protists.
– mostly photosynthetic
– some heterotrophic
– single-celled
– one or two flagella pellicle
contractile
vacuole
nucleus
flagellum
chloroplast
eye spot
19.3 Plantlike Protists
• Dinoflagellates are mostly marine plantlike protists.
– have two flagella
– may be bioluminescent
– have stiff protective
plates
– can cause red tide
Dinoflagellates
19.3 Plantlike Protists
• Multicellular algae are classified by their pigments.
– Green algae contain
chlorophyll a and b.
– Brown algae contain
chlorophyll c.
– Red algae contain
chlorophyll a and
phycoerythrin.
thickening agents used in
ice cream like agar and
carrageen come from
Red Algae!
19.3 Plantlike Protists
Many plantlike protists can reproduce both sexually and
asexually.
• All algae can reproduce asexually.
– Multicellular algae can fragment.
– Chlamydomonas divides into zoospores.
19.3 Plantlike Protists
• Some algae produce sexually.
– Some species alternate generations.
– Sexual reproduction can be triggered by environmental
stress.
19.4 Funguslike Protists
KEY CONCEPT
Funguslike protists decompose organic matter.
19.4 Funguslike Protists
Slime molds and water molds are funguslike protists.
• Slime molds have both funguslike and animallike traits.
– decomposers, like fungi
– can move, like animals
19.4 Funguslike Protists
• Slime molds can be plasmodial or cellular.
– Plasmodial slime molds are giant cells with many nuclei.
– Cellular slime molds contain independent cells.
Watch ‘em move:
http://www.youtube.com/watch?v=3SdadVrVMK4
19.4 Funguslike Protists
• Water molds are freshwater, funguslike protists.
– one type of water mold
caused Great Potato Famine
of Ireland in the 1800’s
– made of branching
strands of cells
– can be parasites of
plants or fish
–If you see a dead-fish with
filiments on it, that’s a
watermold