Transcript Protists: Plant-like Protists and Fungus
Protists: Plant-like Protists and Fungus-like Protists
Plant-like Protists
• Unicellular or Multicellular?
– Both!!
• Autotroph or Heterotroph?
– Autotroph!!
– Uses Chlorophyll or Accessory Pigments • To make their own food • Where do they live?
– Soil – The barks of trees – Fresh water – Salt water
Plant-like Protists
• How are they divided into Phyla?
– Number of cells and complexity • We will learn about six groups.
– Euglenoids – Diatoms – Dinoflagellates – Red Algae – Brown Algae – Green Algae
Plant-like Protists
• Euglenoids are green, unicellular algae that are found mostly in fresh water. • Unlike other algae, euglenoids can be heterotrophs under certain conditions
Plant-like Protists
• Diatoms – Diatoms are unicellular protists – Some float on the surface of freshwater and saltwater – Others attach to objects such as rocks in shallow water. – Diatoms move by oozing slime out of slits in their cell walls. – Cell walls of dead diatoms are used to make toothpastes and household scouring products as well as in swimming pool filters and insecticides.
Plant-like Protists
• Dinoflagellates – Dinoflagellates are unicellular algae covered by stiff plates that look like a suit of armor.
– Dinoflagellates exist in a variety of colors. – All dinoflagellates have two flagella – Can be the cause of a Red Tide • Red Tide - red tides occur most often when there is an increase in nutrients in the water • Red tides are dangerous when the toxins that the algae produce become concentrated in the bodies of organisms that consume the algae
Plant-like Protists
• Red Algae – Almost all red algae are multicellular seaweeds.
– Red algae growing at depths greater than 260 meters. – Carrageenan in Red algae is used in products such as ice creams and hair conditioners. – For people in many Asians cultures, red algae is a nutrient-rich delicacy that is eaten fresh, dried, or toasted.
Plant-like Protists
• Brown Algae – Brown algae contain brown green, yellow, and orange pigments.
– Holdfasts anchor the alga to rocks.
– Stalks support the blades, which are the leaflike structures of the alga.
– Brown algae also have gas-filled sacs called bladders that allow the algae to float upright in the water. – Brown algae flourish in cool, rocky waters. – The giant kelps form large underwater “forests” where many organisms, including sea otters and abalone, live. – Some people eat brown algae for their nutrients and can be found in foods such as puddings and salad dressings.
Plant-like Protists
• Green Algae – All green algae contain green pigments. – Most green algae are unicellular, some form colonies, and a few are multicellular. – An example is green seaweed, washed up on a beach. – Most green algae live in either freshwater or saltwater surroundings. – Few live on land and are found along the bases of trees or in moist soils.
Plant-like Protists
• Saltwater algae bloom versus a freshwater algae bloom – Both are a rapid increase in algae growth due to an increase in nutrient in the water – Saltwater?
• Red Tide – Freshwater?
• Eutrophication – nutrients such as nitrogen and phosphorus build up in a lake or pond over time, causing an increase in the growth of algae.
Plant-like Protists
• Why is eutrophication bad?
– Nutrient increase – Algae increase too much – Algae then dies – Bacteria break down algae – To breakdown all the algae bacteria use up a lot of oxygen – Not enough oxygen for fish and other animals and they die
Fungus-like Protists
• Why Fungus–
like
?
– Have cell walls like fungus – Decomposers like fungi – Reproduce with spores like fungi
Fungus-like Protists
• Why not fungus then?
– Fungus like protist are able to move at some point of their life cycle.
– True fungi do not move!
Fungus-like Protists
• Three types of Fungus-like protists.
– The three types of fungus-like protists are: • water molds • downy mildews • slime molds
Fungus-like Protists
• Water molds and downy mildews – Live in water and moist places – grow as tiny threads that look like a fuzzy covering • What do they do?
– attack food crops, such as potatoes, cabbages, corn, and grapes – Cause of Irish potato famine
Fungus-like Protists
• Slime Molds – live in moist soil and on decaying plants and trees (fallen logs , dead leaves, forest floors).
– Slime molds are often beautifully colored. – They move like an amoeba forming pseudopods.
– Slime molds feed on bacteria, other microorganisms and decaying matter.