{"id":64,"date":"2015-07-17T21:14:10","date_gmt":"2015-07-17T21:14:10","guid":{"rendered":"https:\/\/courses.candelalearning.com\/bio2labsxmaster2\/?post_type=chapter&p=64"},"modified":"2016-01-06T22:01:14","modified_gmt":"2016-01-06T22:01:14","slug":"protists","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/tcc-biolab\/chapter\/protists\/","title":{"raw":"Reading: Protists","rendered":"Reading: Protists"},"content":{"raw":"The goal of this exercise is to learn about the protists. We will study major groups and for most of the groups, we will study representative genera.\r\n

Procedure<\/h2>\r\nFor each specimen:\r\n
    \r\n\t
  1. Read the information thoroughly.<\/li>\r\n\t
  2. Create notes. Your notes will be most helpful if they include a drawing, a description, and significant information such as life cycle, commercial value, ecological significance, and unusual characteristics.<\/li>\r\n<\/ol>\r\n

    Euglenozoans<\/h2>\r\n

    Kinetoplastids<\/h3>\r\nKinetoplastids are flagellated and unicellular. They\u00a0have a dark staining region of mitochondria called a kinetoplast.\r\n\r\nSome kinetoplastids are symbiotic<\/strong> (close) relationships with other organisms.\u00a0Trypanosomes are Kinetoplastids that cause African sleeping sickness. They are transmitted to their human hosts by the bite of a tsetse fly.\u00a0Trypanosoma<\/em> causes African sleeping sickness.\r\n

    Euglena<\/h3>\r\nEuglena are unicellular.\u00a0Many Euglenids feed by phagocytosis. Many species of Euglenids are photosynthetic but can become heterotrophic when sunlight is unavailable (mixotrophs).\r\n\r\nEuglena use flagella for moving. The outer covering called a pellicle<\/strong>, is flexible and assists in moving.\u00a0Some have an eyespot with a photoreceptor is capable of detecting the presence of light.\u00a0Reproduction is asexual.\r\n

    \u00a0Diatoms<\/h2>\r\nDiatoms are the most numerous unicellular algae in the oceans and as such are an important source of food and oxygen. They are also important in freshwater environments. They capture 20 to 25% of solar energy captured by living organisms.\u00a0The cell walls of diatoms contain silica (a component of glass) and are formed in 2 halves like a pillbox.\u00a0Their remains form diatomaceous earth. It is used for filtering agents, and abrasives such as scouring powders.\u00a0Diatoms are a major component of phytoplankton in freshwater and marine environments.\r\n

    Brown Algae<\/h2>\r\nBrown algae are autotrophs (photosynthetic).\u00a0Their characteristic brown color is due to carotenoid pigments.\u00a0They are multicellular and range in size from small to very large. Some are 50 m to 100 m long.\u00a0They are often found along rocky shores in temperate climates.\u00a0The body (thallus<\/i>) contains holdfasts<\/i> for attachment, blades<\/i>, and a stem-like structure that holds the blades is called a stipe<\/i>. Many species have floats that function in floatation.\u00a0Some have gas-filled floats.\u00a0Mucilaginous (slimy) material in the cell walls retards drying in exposed individuals when the tide goes out.\u00a0Most species<\/strong> have a life cycle with alternation of generations<\/strong>.\r\n

    Fucus<\/h3>\r\nFucus<\/em> is a common \"seaweed\" found along the rocky coast.\u00a0Some species of Fucus<\/i> have diploid adults<\/strong>.\r\n\r\n[caption id=\"attachment_254\" align=\"alignnone\" width=\"400\"]\"Photo Figure 1. Gametes are produced in the receptacles.[\/caption]\r\n

    Macrocystis and Nereocystis<\/h3>\r\nMacrocystis and nereocystis are deep-water kelps.\r\n

    Sargassam<\/h3>\r\nSargassam sometimes breaks off to form floating masses. Other marine organisms congregate around these masses.\r\n

    Laminaria<\/h3>\r\nLaminaria is a brown alga that is usually found attached just below the intertidal zone. It has a life cycle with alternation of generations.\r\n\r\n[caption id=\"attachment_255\" align=\"alignnone\" width=\"432\"]\"Zoospores Figure 2. Alternation of Generations[\/caption]\r\n

    Dinoflagellates<\/h2>\r\nProtective cellulose<\/strong> plates cover dinoflagellates and two flagella<\/strong> enable them to move. One of the flagella lies in a transverse groove that causes cell to spin as it moves.\r\n\r\nMost are found in marine or freshwater environments and many are photosynthetic. They are important components of phytoplankton<\/strong> and thus are important in aquatic food chains<\/strong>. This group also includes many heterotrophic and many mixotrophic species.\r\n\r\nSome species are responsible for red tides that kill fish and shellfish (Gymnodinium, Gonyaulax, Pfiesteria).\u00a0Some live as symbiants<\/strong> within some invertebrates. For example, some corals grow faster with dinoflagellates living within their cells.\u00a0Some species are capable of bioluminescence (they produce light).\r\n\r\nBoth sexual and asexual reproduction occur. Sexual reproduction produces cysts which are resistant to unfavorable environmental conditions. Cysts are dormant and become active when environmental conditions improve.\r\n

    Ciliates<\/h2>\r\nThe genus Vorticella<\/em> belongs in this group.\r\n

    Paramecium<\/h3>\r\n[caption id=\"attachment_256\" align=\"alignright\" width=\"240\"]\"Figure Figure 3. Paramecium caudatum<\/em> X 100[\/caption]\r\n\r\nThe\u00a0pellicle<\/strong>\u00a0(outer covering) of paramecium is covered with hundreds of\u00a0cilia<\/strong>.\u00a0They have numerous organelles including a gullet (oral groove) and an anal pore. Ciliates have a large macronucleus and a smaller micronucleus.\r\n\r\nThe micronucleus is involved in sexual and asexual reproduction. Other nuclear activities are handled by the macronucleus.\u00a0The macronucleus is polyploid<\/strong> (approximately 860 N in Paramecium aurelia) and the micronucleus is diploid<\/strong>.\r\n\r\n[caption id=\"attachment_260\" align=\"alignright\" width=\"240\"]\"Conjugation Figure 4. Paramecium X 200[\/caption]\r\n\r\nDuring reproduction, the macronucleus disintegrates. Later, a micronucleus will develop into a macronucleus.\u00a0Most reproduction is asexual (mitosis). Sexual reproduction is by conjugation<\/strong>.\r\n\r\nThe micronucleus will divide by meiosis; 3 of the 4 resulting nuclei will disintegrate as will the macronucleus. The remaining haploid nucleus will divide by mitosis producing an individual with two haploid nuclei. Two conjugating individuals will each exchange one of the nuclei. The two haploid nuclei will then fuse producing a diploid nucleus.\r\n\"Two\r\n\"Three\r\n\"The\r\n

    Red Algae<\/h2>\r\nRed algae are mostly multicellular and are found mainly in warmer, tropical oceans.\u00a0Their red color is due to an accessory photosynthetic pigment<\/strong> called phycoerythrin. The accessory pigments of red algae are able to absorb blue and green light. This allows some species to survive in deep waters where blue and green light predominates.\r\n\r\nSome species are filamentous<\/strong> but most have a complex pattern of branching.\u00a0Some coralline forms deposit calcium carbonate in their cell walls, which contributes to the development of coral reefs.\r\n

    Green Algae<\/h2>\r\nFour common forms of green algae are single-celled, colonial<\/strong>, filamentous<\/strong>, and multicellular<\/strong>.\u00a0Green algae are thought to be ancestors of the first plants. Both kinds of organisms have the following characteristics in common:\r\n
      \r\n\t
    1. They have a cell wall<\/strong> that contains cellulose<\/strong>.<\/li>\r\n\t
    2. They have chlorophyll<\/strong> a and b.<\/li>\r\n\t
    3. They store their food as starch<\/strong> inside the chloroplast<\/strong>.<\/li>\r\n<\/ol>\r\nMost species are freshwater but there are many marine species. Some live in damp soil.\r\n

      Chlamydomonas<\/h3>\r\nChlamydomonas is a single-celled organism with two\u00a0flagella<\/strong>.\u00a0Although this organism is a single cell, the life cycle is similar to that with haploid adults<\/strong>.\r\n\r\n[caption id=\"attachment_260\" align=\"alignnone\" width=\"479\" class=\"none\"]\"Adults, Figure 5. Chlamydomonas' life cycle[\/caption]\r\n\r\nIt reproduces asexually (by mitosis) when conditions are favorable.\u00a0Sexual reproduction<\/strong> occurs when conditions become unfavorable. The zygote<\/strong> forms a thick-walled zygospore that is resistant to environmental extremes and divides by meiosis when environmental conditions become favorable.\r\n\r\nMost species<\/strong> of Chlamydomonas are isogamous (both gametes are the same size; they are isogametes), some are oogamous (gametes are two sizes; the larger gametes are eggs, the smaller ones are sperm).\r\n

      Volvox<\/h3>\r\nVolvox<\/strong> is a colonial green algae.\u00a0The cells are arranged in a gelatinous sphere with two flagella directed to the outside.\u00a0They divide asexually to produce a daughter colony.\r\n\r\nSome cells are specialized to produce sperm and eggs for sexual reproduction.\u00a0Specialization of cells as seen in the reproductive cells is a characteristic of multicellular organisms. Volvox is considered to be a colony because it appears to be intermediate between a group of individual cells and a multicellular organism.\r\n

      Spirogyra<\/h3>\r\nSpirogyra<\/strong> is a filamentous<\/strong> form.\u00a0It has a ribbonlike spiral-shaped chloroplast.\u00a0The life cycle has haploid adults<\/em>.\r\n\r\nSexual reproduction occurs by conjugation<\/strong>. Conjugation refers to the process where gametes are transferred from one individual to another by a connection between the two.\r\n\r\nThe zygote is resistant and overwinters. In the spring, it divides by meiosis to produce haploid filaments.\r\n

      Ulva<\/h3>\r\nUlva is multicellular with a leaflike body that is two cells thick but up to one meter long.\u00a0The life cycle is alternation of generations. Both the haploid and the diploid generations look alike (isomorphic<\/strong>).\r\n

      Tubulinids<\/h2>\r\n[caption id=\"attachment_263\" align=\"alignright\" width=\"229\"]\"Microscope Figure 7. Amoeba proteus<\/em> X 100[\/caption]\r\n\r\nTubulinids move by cytoplasmic<\/strong> extensions called pseudopodia<\/strong>.\u00a0They feed by phagocytizing<\/strong> (engulfing) their prey.\u00a0Tubulinids are found in soil, marine, and freshwater environments. Amoeba proteus<\/em> (figure 7) is found in freshwater.\u00a0<\/span>\r\n\r\nAmoeba movement and phagocytosis (video)<\/a><\/span>","rendered":"

      The goal of this exercise is to learn about the protists. We will study major groups and for most of the groups, we will study representative genera.<\/p>\n

      Procedure<\/h2>\n

      For each specimen:<\/p>\n

        \n
      1. Read the information thoroughly.<\/li>\n
      2. Create notes. Your notes will be most helpful if they include a drawing, a description, and significant information such as life cycle, commercial value, ecological significance, and unusual characteristics.<\/li>\n<\/ol>\n

        Euglenozoans<\/h2>\n

        Kinetoplastids<\/h3>\n

        Kinetoplastids are flagellated and unicellular. They\u00a0have a dark staining region of mitochondria called a kinetoplast.<\/p>\n

        Some kinetoplastids are symbiotic<\/strong> (close) relationships with other organisms.\u00a0Trypanosomes are Kinetoplastids that cause African sleeping sickness. They are transmitted to their human hosts by the bite of a tsetse fly.\u00a0Trypanosoma<\/em> causes African sleeping sickness.<\/p>\n

        Euglena<\/h3>\n

        Euglena are unicellular.\u00a0Many Euglenids feed by phagocytosis. Many species of Euglenids are photosynthetic but can become heterotrophic when sunlight is unavailable (mixotrophs).<\/p>\n

        Euglena use flagella for moving. The outer covering called a pellicle<\/strong>, is flexible and assists in moving.\u00a0Some have an eyespot with a photoreceptor is capable of detecting the presence of light.\u00a0Reproduction is asexual.<\/p>\n

        \u00a0Diatoms<\/h2>\n

        Diatoms are the most numerous unicellular algae in the oceans and as such are an important source of food and oxygen. They are also important in freshwater environments. They capture 20 to 25% of solar energy captured by living organisms.\u00a0The cell walls of diatoms contain silica (a component of glass) and are formed in 2 halves like a pillbox.\u00a0Their remains form diatomaceous earth. It is used for filtering agents, and abrasives such as scouring powders.\u00a0Diatoms are a major component of phytoplankton in freshwater and marine environments.<\/p>\n

        Brown Algae<\/h2>\n

        Brown algae are autotrophs (photosynthetic).\u00a0Their characteristic brown color is due to carotenoid pigments.\u00a0They are multicellular and range in size from small to very large. Some are 50 m to 100 m long.\u00a0They are often found along rocky shores in temperate climates.\u00a0The body (thallus<\/i>) contains holdfasts<\/i> for attachment, blades<\/i>, and a stem-like structure that holds the blades is called a stipe<\/i>. Many species have floats that function in floatation.\u00a0Some have gas-filled floats.\u00a0Mucilaginous (slimy) material in the cell walls retards drying in exposed individuals when the tide goes out.\u00a0Most species<\/strong> have a life cycle with alternation of generations<\/strong>.<\/p>\n

        Fucus<\/h3>\n

        Fucus<\/em> is a common “seaweed” found along the rocky coast.\u00a0Some species of Fucus<\/i> have diploid adults<\/strong>.<\/p>\n

        \"Photo<\/p>\n

        Figure 1. Gametes are produced in the receptacles.<\/p>\n<\/div>\n

        Macrocystis and Nereocystis<\/h3>\n

        Macrocystis and nereocystis are deep-water kelps.<\/p>\n

        Sargassam<\/h3>\n

        Sargassam sometimes breaks off to form floating masses. Other marine organisms congregate around these masses.<\/p>\n

        Laminaria<\/h3>\n

        Laminaria is a brown alga that is usually found attached just below the intertidal zone. It has a life cycle with alternation of generations.<\/p>\n

        \"Zoospores<\/p>\n

        Figure 2. Alternation of Generations<\/p>\n<\/div>\n

        Dinoflagellates<\/h2>\n

        Protective cellulose<\/strong> plates cover dinoflagellates and two flagella<\/strong> enable them to move. One of the flagella lies in a transverse groove that causes cell to spin as it moves.<\/p>\n

        Most are found in marine or freshwater environments and many are photosynthetic. They are important components of phytoplankton<\/strong> and thus are important in aquatic food chains<\/strong>. This group also includes many heterotrophic and many mixotrophic species.<\/p>\n

        Some species are responsible for red tides that kill fish and shellfish (Gymnodinium, Gonyaulax, Pfiesteria).\u00a0Some live as symbiants<\/strong> within some invertebrates. For example, some corals grow faster with dinoflagellates living within their cells.\u00a0Some species are capable of bioluminescence (they produce light).<\/p>\n

        Both sexual and asexual reproduction occur. Sexual reproduction produces cysts which are resistant to unfavorable environmental conditions. Cysts are dormant and become active when environmental conditions improve.<\/p>\n

        Ciliates<\/h2>\n

        The genus Vorticella<\/em> belongs in this group.<\/p>\n

        Paramecium<\/h3>\n
        \"Figure<\/p>\n

        Figure 3. Paramecium caudatum<\/em> X 100<\/p>\n<\/div>\n

        The\u00a0pellicle<\/strong>\u00a0(outer covering) of paramecium is covered with hundreds of\u00a0cilia<\/strong>.\u00a0They have numerous organelles including a gullet (oral groove) and an anal pore. Ciliates have a large macronucleus and a smaller micronucleus.<\/p>\n

        The micronucleus is involved in sexual and asexual reproduction. Other nuclear activities are handled by the macronucleus.\u00a0The macronucleus is polyploid<\/strong> (approximately 860 N in Paramecium aurelia) and the micronucleus is diploid<\/strong>.<\/p>\n

        \"Conjugation<\/p>\n

        Figure 4. Paramecium X 200<\/p>\n<\/div>\n

        During reproduction, the macronucleus disintegrates. Later, a micronucleus will develop into a macronucleus.\u00a0Most reproduction is asexual (mitosis). Sexual reproduction is by conjugation<\/strong>.<\/p>\n

        The micronucleus will divide by meiosis; 3 of the 4 resulting nuclei will disintegrate as will the macronucleus. The remaining haploid nucleus will divide by mitosis producing an individual with two haploid nuclei. Two conjugating individuals will each exchange one of the nuclei. The two haploid nuclei will then fuse producing a diploid nucleus.
        \n\"Two
        \n\"Three
        \n\"The<\/p>\n

        Red Algae<\/h2>\n

        Red algae are mostly multicellular and are found mainly in warmer, tropical oceans.\u00a0Their red color is due to an accessory photosynthetic pigment<\/strong> called phycoerythrin. The accessory pigments of red algae are able to absorb blue and green light. This allows some species to survive in deep waters where blue and green light predominates.<\/p>\n

        Some species are filamentous<\/strong> but most have a complex pattern of branching.\u00a0Some coralline forms deposit calcium carbonate in their cell walls, which contributes to the development of coral reefs.<\/p>\n

        Green Algae<\/h2>\n

        Four common forms of green algae are single-celled, colonial<\/strong>, filamentous<\/strong>, and multicellular<\/strong>.\u00a0Green algae are thought to be ancestors of the first plants. Both kinds of organisms have the following characteristics in common:<\/p>\n

          \n
        1. They have a cell wall<\/strong> that contains cellulose<\/strong>.<\/li>\n
        2. They have chlorophyll<\/strong> a and b.<\/li>\n
        3. They store their food as starch<\/strong> inside the chloroplast<\/strong>.<\/li>\n<\/ol>\n

          Most species are freshwater but there are many marine species. Some live in damp soil.<\/p>\n

          Chlamydomonas<\/h3>\n

          Chlamydomonas is a single-celled organism with two\u00a0flagella<\/strong>.\u00a0Although this organism is a single cell, the life cycle is similar to that with haploid adults<\/strong>.<\/p>\n

          \"Adults,<\/p>\n

          Figure 5. Chlamydomonas’ life cycle<\/p>\n<\/div>\n

          It reproduces asexually (by mitosis) when conditions are favorable.\u00a0Sexual reproduction<\/strong> occurs when conditions become unfavorable. The zygote<\/strong> forms a thick-walled zygospore that is resistant to environmental extremes and divides by meiosis when environmental conditions become favorable.<\/p>\n

          Most species<\/strong> of Chlamydomonas are isogamous (both gametes are the same size; they are isogametes), some are oogamous (gametes are two sizes; the larger gametes are eggs, the smaller ones are sperm).<\/p>\n

          Volvox<\/h3>\n

          Volvox<\/strong> is a colonial green algae.\u00a0The cells are arranged in a gelatinous sphere with two flagella directed to the outside.\u00a0They divide asexually to produce a daughter colony.<\/p>\n

          Some cells are specialized to produce sperm and eggs for sexual reproduction.\u00a0Specialization of cells as seen in the reproductive cells is a characteristic of multicellular organisms. Volvox is considered to be a colony because it appears to be intermediate between a group of individual cells and a multicellular organism.<\/p>\n

          Spirogyra<\/h3>\n

          Spirogyra<\/strong> is a filamentous<\/strong> form.\u00a0It has a ribbonlike spiral-shaped chloroplast.\u00a0The life cycle has haploid adults<\/em>.<\/p>\n

          Sexual reproduction occurs by conjugation<\/strong>. Conjugation refers to the process where gametes are transferred from one individual to another by a connection between the two.<\/p>\n

          The zygote is resistant and overwinters. In the spring, it divides by meiosis to produce haploid filaments.<\/p>\n

          Ulva<\/h3>\n

          Ulva is multicellular with a leaflike body that is two cells thick but up to one meter long.\u00a0The life cycle is alternation of generations. Both the haploid and the diploid generations look alike (isomorphic<\/strong>).<\/p>\n

          Tubulinids<\/h2>\n
          \"Microscope<\/p>\n

          Figure 7. Amoeba proteus<\/em> X 100<\/p>\n<\/div>\n

          Tubulinids move by cytoplasmic<\/strong> extensions called pseudopodia<\/strong>.\u00a0They feed by phagocytizing<\/strong> (engulfing) their prey.\u00a0Tubulinids are found in soil, marine, and freshwater environments. Amoeba proteus<\/em> (figure 7) is found in freshwater.\u00a0<\/span><\/p>\n

          Amoeba movement and phagocytosis (video)<\/a><\/span><\/p>\n\n\t\t\t

          \n\t\t\t

          Candela Citations<\/h3>\n\t\t\t\t\t
          \n\t\t\t\t\t\t
          \n\t\t\t\t\t\t\t
          CC licensed content, Shared previously<\/div>