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Transcript of Mader: Biology 8 th Ed. The Protists Chapter 22. Mader: Biology 8 th Ed. Outline General Biology...
Mader: Biology 8th Ed.
The Protists
Chapter 22
Mader: Biology 8th Ed.
Outline
• General Biology• Evolution• Diversity
– Green Algae– Red Algae– Brown Algae– Diatoms– Dinoflagellates
• Diversity– Euglenoids– Zooflagellates– Pseudopods– Ciliates– Sporozoans– Slime Molds– Water Molds
Mader: Biology 8th Ed.
General Biology of the Protists
• Protists are classified in the domain Eukarya and the kingdom Protista.– Most are unicellular, but have achieved a
high level of complexity.– Asexual reproduction is common, but
sexual reproduction can occur when the environment becomes stressful.
SporesCysts
Mader: Biology 8th Ed.
Origin of Eukaryotic Cell
Mader: Biology 8th Ed.
Evolution of Protists
• Complexity and diversity of protists makes them difficult to classify.– Cannot be classified as plants, animals, or
fungi.– Has been suggested protists could be
split into as many as a dozen kingdoms.
Mader: Biology 8th Ed.
Diversity of Protists
• Green Algae– Green algae (phylum Chlorophyta).
Chlamydomonas Unicellular Usually reproduces asexually
Forms spores and zoospores when growth conditions are unfavorable.
Mader: Biology 8th Ed.
Mader: Biology 8th Ed.
Green Algae
– SpirogyraUnbranched, filamentous alga found in
masses on the surfaces of standing water.
Mader: Biology 8th Ed.
Green Algae
– Multicellular UlvaStonewortsChara
Mader: Biology 8th Ed.
Green Algae
– Colonial Volvox
Mader: Biology 8th Ed.
Red Algae
• Red Algae (phylum Rhodophyta)– Multicellular, and live mostly in warmer
seawater.Usually much smaller and more delicate
than brown algae.Economic Importance
Agar
Mader: Biology 8th Ed.
Brown Algae
• Brown Algae (phylum Phaeophyta)– Have chlorophylls a and c in their
chloroplasts and a carotenoid pigment.– Often observed on rocky coasts in north
temperate zone.SeaweedsKelpFucus
Mader: Biology 8th Ed.
Brown Algae
Mader: Biology 8th Ed.
The Diatoms
• Diatoms (phylum Bacillariophyta) are the most numerous unicellular algae in the oceans.– Significant portion of phytoplankton.– Structure composed of two valves, with
the larger valve acting as a lid.– Cell wall has outer layer of silica.
Mader: Biology 8th Ed.
The Dinoflagellates
• Most dinoflagellates (phylum Pyrrophyta) are unicellular.– Usually bounded by protective cellulose
plates impregnated with silicates.Typically contain two flagella.Chloroplasts vary in color.Usually reproduce asexually.Some genera may cause red tide.
Mader: Biology 8th Ed.
Diatoms and Dinoflagellates
Mader: Biology 8th Ed.
The Euglenoids
• Euglenoids (phylum Euglenophyta) are small freshwater unicellular organisms.– Difficult to classify.– Have two flagella and an eyespot (shades
a photoreceptor).– Bound by flexible pellicle.
Mader: Biology 8th Ed.
Euglena
Mader: Biology 8th Ed.
The Zooflagellates
• Zooflagellates (phylum Zoomastigophora) are colorless heterotrophs.– Most are symbiotic and many are
parasitic.– Well known for causing various diseases
in humans.African sleeping sicknessGiardia lamblia
Mader: Biology 8th Ed.
Zooflagellates
Mader: Biology 8th Ed.
Protists with Pseudopods
• Pseudopods form when cytoplasm streams forward in a particular direction.– Amoeboids (phylum Rhizopoda) are
protists that move and ingest their food with pseudopods.
Phagocytize food.– Foraminiferans (phylum Foraminifera) and
radiolarians (phlyum Actinopoda) both have a skeleton (test).
Mader: Biology 8th Ed.
Protists with Pseudopods
Mader: Biology 8th Ed.
The Ciliates
• Ciliates (phylum Ciliophora) are most complex of the protozoans.– Hundreds of cilia beat in coordinated
rhythm.– Most are holozoic.– Divide by transverse binary fission during
asexual reproduction.– High level of diversity.
Mader: Biology 8th Ed.
Ciliates
Mader: Biology 8th Ed.
The Sporozoans
• Sporozoans (phylum Apicomplexa) are nonmotile parasites.– Most widespread human parasite is
Plasmodium vivax, the cause of one form of malaria.
Mader: Biology 8th Ed.
Plasmodium vivax Life Cycle
Mader: Biology 8th Ed.
Slime Molds
• Plasmodial Slime Molds– (phylum Myxomycota) usually exist as a
plasmodium.Diploid, multinucleated, cytoplasmic
mass enveloped by a slime sheath. Sporangium produces spores.
• Cellular Slime Mold– (phylum Acrasiomycota) exists as
individual amoeboid cells.
Mader: Biology 8th Ed.
Plasmodial Slime Molds
Mader: Biology 8th Ed.
Water Molds
• Water molds (phylum Oomycota) usually live in the water and form furry growths when they parasitize fish and decompose remains.– Have filamentous body with cell walls
largely composed of cellulose.
Mader: Biology 8th Ed.
Review
• General Biology• Evolution• Diversity
– Green Algae– Red Algae– Brown Algae– Diatoms– Dinoflagellates
• Diversity– Euglenoids– Zooflagellates– Pseudopods– Ciliates– Sporozoans– Slime Molds– Water Molds
Mader: Biology 8th Ed.