kingdom- protista (protists) common characteristics of all protists: -cell type-eukaryote...
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Kingdom- Protista (protists)
Common Characteristics of all protists:
-cell type-eukaryote-unicellular and multicellular-microscopic-live in moist environment
Protists are grouped into categories based on the way they feed
1. protozoans-animal-like protists
-feed by ingestion
-all are unicellular
2. algae- plant-like protists
-make own food by photosynthesis (autotroph)
-unicellular and multicellular
3. slime molds and mildew- feed by decomposition
Major Roles of Protists
1. Algae (plant-like protist) is the base of the aquatic food chain
2. Slime molds decompose and recycle nutrients
3. Causes many diseases (ex. Malaria)
Protozoans (animal-like protists)
Includes 4 main groups:
1. Amoebas – have no definate shape-have extensions of the
cytoplasm called pseudopodia (used to move and feed)
-most live in saltwater and must constantly take in
water to dilute the salt and pump excess out in vacuoles
-most reproduce asexually (1 parent produces an offspring identical to parent)
2. flagellates- have flagella-move by whipping the tail-are beneficial and harmful
3.ciliates- have cila (short hair-like extensions)-live in aquatic areas (ex. Paramecium)
4. sporozoans-produce spores-spores-reproductive cell that forms without
fertilization and produces new offsprings
-live inside a host such as the intestines or blood (these are the ones that cause disease like malaria)
-all are parasites
Algae (plant-like protists)-unicellular and multicellular
phytoplankton (unicellular)
-a major producer of nutrients and oxygen in the aquatic ecosystem
-base of the aquatic food chain
multicellular plant protists are much like a plant but lack roots, stems, leaves
6 algae phyla:1. euglenoids-unicellular, aquatic
-feed like an animal and plant
2. diatoms-golden algae –unicellular-have shells that have the pigment carotenoid
that gives it a gold color-store food as oil-organisms that eat these have a oily taste-as these die, their shells sink to the bottom and are mined and used as abrasives such as in toothpaste
3. dinoflagellates-several produce toxins and some are lethal
-red tide –due to numerous dynoflagellates with reddish color (40-60 million/liter of water)
-cannot harvest shellfish during red tide because their tissue may have the toxins in it
4. Red algae- marine seaweed-body area of these is called the thallus-have a pigment called phycobilins-green,
blue, violet color
5. brown algae (kelp)-live on rocky coast of ocean floor-the chlorophyll in it is yellow brown calledfucaxanthin-many have air bladders that help it to float-food habitat for marine organisms
6. green algae-has the major pigment chlorophyll-can reproduce by fragmentation (breaks off and each piece can grow a new organism)
Fungi-like protists
-includes slime molds, water molds and downy mildews
-the decompose like fungi but do not have all the characteristics of fungi
3 phyla of fungus-like protist:
• 1. slime molds
• 2. water molds
• 3. downy mildew
Slime molds:
• Exist in many colors
• Live in cool, moist, shady areas
• Grow on organic matter like rotting leaves and stumps
• Reproduce similar to fungi (release spores)
Water molds:
• Liver in water or moist places
• Most feed on dead organic matter
• Appear as fuzzy growths on decaying matter
Downy mildew:
• Causes many plant diseases because they are plant parasites
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