Algae – Plant Like Protists
Algae – Plant Like Protists
Make-Up Assignment: Using the notes below as a guide, look up the organisms you are required to draw on the internet or in a book. Draw the organism in the circles provided and write a description of the organism. All websites or books used must be recorded as references to receive credit. Grade:__/13 Protists Eukaryotes, most are unicellular, but can be multicellular or colonial. Colonies are individuals cells that are associated with one another. Cells contain a nucleus and membrane bound organelles such as mitochondria and chloroplasts. Flagella and/or cilia may be used for locomotion and have microtubules. (microtubules are not present in prokaryotes) Include plant-like protists (typically referred to as algae), animal-like protists (protozoans), and fungus-like protists. Life cycles include a haploid and a diploid phase. If the gametes are similar it is considered isogamy. If the gametes are differed (large egg, smaller flagellated sperm) it is heterogamy. Algae – Plant Like Protists Divisions of algae – based on color pigments and chlorophyll types. Green Algae, Red Algae, Fire Algae, Brown Algae, Yellow-green Algae, Golden-brown Algae Protists are divided into supergroups. Supergroup Archaeplastids: unicellular, colonial or multicellular. Cells contain plastids. Are photosynthetic. Green Algae: Contain chlorophyll a and b. Most are unicellular, but do exist in colonies or filaments. Believed to have given rise to higher plants. Divided into two subgroups: chlorophytes and charophytes. Chlorophytes: many occur in colonial forms. Have a definite cell wall. Ex. Volvox: colony of cells. Is a hollow sphere with cells arranged in a single layer around an aquatic center. All flagella in the colony operate to move the volvox in a single direction. (flagella work together) Draw a picture of Volvox in the circle provided. Write a description of its appearance below. Carophytes: filament (end-to-end) chain of cells. Some are branched and others are unbranched. Ex. Spirogyra: unbranched Carophyte. Found in green masses on the surface of ponds and streams. Have chloroplasts which resemble ribbon twisted into a helix. Can undergo conjugation to exchange genetic information. Note: pyrenoids aid in CO2 fixation for chloroplasts in algae and hornworts Spirogyra anatomy Draw: Spirogyra Spirogyra Conjugation Describe Spirogyra below. Red Algae: mulitcellular seaweeds with a red pigment and a blue pigment (in addition to chlorophyll –green) Live in warm salt water. Maybe filamentous or branched. Have economic value in making agar. (agar is used in pharmaceuticals, laboratories, and in food preparation. Considered the most beautiful of the algae. Supergroup Chromalveolates Stramenophiles: have flagella or are descended from organisms with flagella. One flagella is longer than the other and has hair-like projections. Brown Algae: have chlorophyll a and c and carotenoid pigmen (causes coloration) Multicultural species are found on rocky coasts in the north temperate zone. Cell walls help them to retain water, necessary since they are exposed to air when tide goes out. Ex. Kelp – giant and smaller species. Can occur in large groups, may form free-floating masses. Are used as a food source by people. Only protist that has differentiated tissue – vascular system. Draw a picture of Kelp below. Write a description of the kelp. Diatoms: have silica shell – has a top (valve) and bottom half. Top half fits over bottom half like a lid. Orange-yellow color. Diatoms reproduce asexually – each cell receives an old valve…making daughter cells smaller than the parent cells. When diatoms reach 30% of their original size they reproduce sexually. Gold Brown Algae: unicellular or colonial. Have two flagella with hairs. Water Molds: parasitic protists. May parasitize fish, potatoes, grapes, and other organisms. Also colonize dead organisms and aid in decomposition. Resemble fungus, but cell walls contain cellulose (not chitin). (reproduction also differs form fungi). Protozoans – Animal Like Protists Classes of Protozoans: ameba like, flagella-bearing, cilia bearing, and the apicomplexans (parasitic) Aveolates: unicellular protists with small sacs (aveoli) under the plasma membrane. Dinoflagellates: unicellular. Have protective cellulose plates that also contain silicates. Most have 2 flagella, one wraps around the organism and can be used to help the organism spin, the other flagellum is used as a rudder. Some are luminescent. Important food source for marine organisms b/c make up part of plankton. Can cause a red tide if numbers become too high. Release a neurotoxin that can cause large scale fish kills and make shellfish poisonous to consume. Ciliates: unicellular that use cilia for movement. Most structurally complex of protozoa. Includes Paramecium. Ingest their food, digest it, absorb nutrient into the cytoplasm and release waste through an anal pore. Contractile vacuole removes excess water. Have 2 nuclei (macro – metabolism and micro – reproduction) Reproduce asexually through binary fission or sexually utilizing conjugation. Micronuclei undergo meiosis and one is exchanged with the other cell. Micronuclei merge to form macronuclei. Draw a picture of a paramecium below. Write a description of the appearance of the paramecium. Apicomplexans: aka sprozoans. All are parasitic. Cause diseases such as malaria and some forms of pneumonia. Anopheles mosquitoes pick up parasitized blood which contain gametocytes (gamete (sex) cells) of Plasmodium vivax from an infected human. Gametes fuse and divide to produce sporozoites. Sporozoites migrate to mosquito’s salivary gland. Mosquito feeds on 2nd human, and sporozoites enter human blood stream and move to the liver. Asexual spores are produced in liver cells and enter red blood cells where they feed. When rbcs (red blood cells) burst, spores invade new rbcs and reproduce. Some spores become gametocytes and may be taken up by another mosquito. Supergroup Excavates: zooflagellates that may lack mitochondria (or mitochondria may be present, but unusual). Have very deep oral grooves. Euglenids: freshwater unicellular organisms. 1/3 have chloroplasts, 2/3 do not. Have two flagella, one is longer then the other and has hairs on it. Is both animal like and plant like. Draw a Euglena in the space below. Write a description of the appearance of Euglena. Parabasalids: have fibrous connection between golgi body and flagella. Some are parasitic. Lack mitochondria and rely on fermentation for ATP. Diplomonad: have 2 nuclei and 2 flagella. May cause diarrhea if ingested. Often carried by beavers. (why should we boil our water if we’re hiking before we drink it?) Lack mitochondria and rely on fermentation for ATP. Kinetoplastids: unicellular with flagella. Have lare masses of DNA in mitochondria. Some are parasitic. Cause African sleeping sickness and Chagas disease. 45,000 people die per year due to infections of Kinetoplastids. Supergroup Amoebozoans: animal like protists that use a pseudopod, a false foot, which is an extension of the cytoplasm used to pull cell forward (cytoplasmic streaming) Amoeboids: move and ingest food using pseudopods. Eat via phagocytosis, which places food into a vacuole where digestion occurs. Have contractile vacuoles for water removal. Can cause dysentery. If get out of digestive tract and into the body, can be fatal. Phagocytosis Draw in Amoeba in the space below and write a description of its appearance. Slime Molds: help decompose plant material. Have diploid and haploid phases of the life cycle. May produce fruiting bodies that resemble fungi. However, the vegetative state is mobile and the cells lack cell walls (therefore they cannot be fungi). Feeds via phagocytosis as it “crawls” across decaying plant matter. Visually may resemble vomit (dog vomit slime mold) or jelly. Supergroup Opisthokonts: unicellular and multicellular protists. Some are closely related to sponges (an animal). Others (such as nucleariids) are closely related to fungi, but lack the cell walls. Supergroup Rhizarians: have thin, thread-like pseudopods. Extremely important to fossil records, foraminiferans types (a group of Rhizarians) are very specific to period of time and so can be used to date rocks and other fossils found within these rocks.