File - MJHS White Team
Transcription
File - MJHS White Team
Kingdom Protista Chapter 7: Protists (p.226-235) Characteristics A. larger than monerans, but still microscopic B. unicellular (single-celled organisms) C. eukaryotic – they DO contain a nucleus as well as other cell parts that monerans lack Characteristics D. Living Conditions 1. most live in water (salty & fresh) 2. some live in soil 3. others live inside other organisms (can be parasitic or symbiotic) 4. can live alone or in colonies Characteristics E. Evolved approximately 1.5 billion years ago F. Symbiotic relationships between bacteria (monerans) led to development of protists Symbiotic Relationships Between Bacteria… 1. specific functioning bacteria lived inside other independently functioning bacteria 2. over time, these “specialized” cells lost their independence and began working as a team leading to the formation of a nucleus and individual hereditary material Characteristics G. Protists can function as autotrophs, heterotrophs, or both H. Grouped into 3 categories 1. animal-like 2. plant-like 3. fungus-like Animal-Like Protists A. Sometimes called protozoa – first animals B. Do not contain a cell wall C. Able to move Organized into 4 groups – sarcodines, ciliates, zooflagellates, and sporozoans Group 1 – Sarcodines (characteristics) a. Characterized by extensions of the cell membrane and cytoplasm – pseudopod (false foot) Used for obtaining/engulfing food Used for movement from one place to another Amoeba b. Amoeba – the most common sarcodine Sarcodines (characteristics) c. Contractile vacuoles regulate the amount of water in the sarcodine d. Reproduce asexually by fission – complex division of once cell into two Group 2 – Ciliates (characteristics) a. Surrounded by cilia – small hairlike projections that aid in movement by working as “tiny ores” Paramecium b. Paramecium – most common ciliate Ciliates (characteristics) c. Contain two nuclei Large nucleus controls life functions Small nucleus involved in conjugation Reproduction The coming together of two ciliates to exchange hereditary information Form of sexual reproduction Group 3 – Zooflagellates (characteristics) a. Characterized by flagellum (plural) Whiplike structure to aid in movement Usually contain 1 to 8 flagella on average Zooflagellates (characteristics) b. Usually live inside a host Parasitic – harm their host and may cause diseases in humans and animals Symbiotic – may have no effect on host, or may benefit host (termites) Trichonympha - This flagellated protozoan commonly inhabits the digestive tract of the termite. Trichonympha and the termite form a symbiotic relationship. In this mutualistic relationship, the protist eats the wood in the gut of the termite. Group 4 – Sporozoans (characteristics) a. No movement b. All are parasitic – feed on cells and body fluids of host Plasmodium c. Plasmodium – most famous sporozoan: causes malaria disease, transported by mosquitoes d. Reproduce by forming and releasing spores that travel into new host and usually cause harm or disease in new host Plant-Like Protists most are able to move autotrophic – use light to make their own food from simple raw materials most are “flagellates” (move by flagella) – specifically called phytoflagellates organized into 3 groups – eugleana, diatoms, dinoflagellates Euglenas pouch with two flagella reddish “eyespot” chloroplasts – green structures used in food making process Diatoms a. contain very attractive, glassy, colorful shells • • shells are left behind after death over time, shells pile up in layers forming deposits of diatomaceous earth Diatomaceous Earth • coarse, powdery material • mild abrasive, good for polishing • reflects light • • used in toothpastes, scouring cleaners used in highway and road paint Dinoflagellates a. Cause “Red Tide” – • • • reproduce so rapidly that they change the color of the water tide can be many colors some give off toxins that poison the water killing organisms and poisoning water supplies Dinoflagellates b. reflective and glowing • • oceans at night will often sparkle and glow due to the dinoflagellates may cause illnesses in people or other organisms Fungus-Like Protists A. can have a great effect on humans 1. Great Potato Famine in Ireland (184546)...destroyed entire potato crop and caused a famine which killed about 1/3 of Ireland's entire population Fungus-Like Protists 2. cause fungus-like diseases on all types of plants/animals B. heterotrophic – obtain food from other sources Slime Molds C. interesting fungus-like protist = slime molds 1. 2. at one point in life they are moist, flat, shapeless blobs reproduction involves the production of a fruiting body, which contains spores How are we going to learn about the different groups of protists? You will be the teachers! There are 4 groups of protists: Animal Like Protists Sarcodines (1) Ciliates (2) Zooflagellates (3) Sporozoan (4) Plant Like Protists Euglenas (5) Diatoms (6) Dinoflagellates (7) Fungus Like Protists (8) You will be broken up into groups, and will teach about one of the groups of protists!