Archaeplastida - ANS--A monophyletic group that descended from an ancient protist that engulfed a cyanobacterium. Includes red algae, green algae, and land plants. Phycoerythrin - ANS--Pigment that masks the green of chlorophyll. This pigment allows red

Archaeplastida - ANS--A monophyletic group that descended from an ancient protist that engulfed a cyanobacterium. Includes red algae, green algae, and land plants. Phycoerythrin - ANS--Pigment that masks the green of chlorophyll. This pigment allows red algae to absorb blue and green light (allowing them to live in deep water). Red Algae Rhodophytes - ANS--Usually multicellular. No flagellated gametes, they depend on currents for fertilization. Cell walls of corraline algae are hardened by calcium carbonate. Porphyra - ANS--A foliose red algae eaten as nori and used in fish pellets. Green Algae - ANS--Named for grass-green chloroplasts. Include chlorophytes and charophytes. Chlorophytes - ANS--Unicellular, colonial, or multicellular. Include euglena and chlamydomonas. Mostly freshwater but also marine and terrestrial. Chlamydomonas nivalis - watermelon snow - has carotenoid pigment as well as chlorophyll. Cytoplasm - ANS--Cyto means cell. Plasm means mold. Chlorophyll - ANS--Chloros means green. Phyllon means leaf. 3 Mechanisms of Chlorophyte Evolution - ANS--1. Forming colonies or filamentous masses. 2. Forming multicellular bodies by cell division and differentiation. 3. Repeated division of nuclei without cytoplasmic division. Forming colonies or filamentous masses - ANS--Wall composed of thousands of biflagellated cells embedded in gelatinous matrix. Cells connected by cytoplasm. Example: volvox - seen in stringy masses of pond scum. Forming multicellular bodies by cell division and differentiation - ANS--Thallus, blades, holdfast. Example: ulva or sea lettuce. Repeated division of nuclei without cytoplasmic division - ANS--Branched filaments are multinucleate. Thallus is one huge supercell. Similarities between green algae and land plants - ANS--1. Multicellularity. 2. Eukaryotic. 3. Photosynthetic autotrophs. 4. Cellulose cell walls. 5. Chloroplasts with chlorophylls A or B. Charophytes - ANS--Shallow, freshwater dwelling, branched, multicellular green algae. Can extend above water surface. Known as muskgrass or skunk weed because of odor. Sperm in antheridium; egg in oogonium. Similarities between charophytes and land plants - ANS--1. Rings of cellulose-synthesizing proteins in plasma membrane. 2. Peroxisomal enzymes that minimize loss of organic products. 3. Similar structure of flagellated sperm. 4. Formation of phragmoplast. 5. Presence of sporopollenin-like polymer. 6. Similar nuclear and chloroplast gene sequences. Phragmoplast - ANS--A group of microtubules that give rise to cell plate then new cell wall between daughter cells. Phragmo means fenced; plast means formed. Sporopollenin - ANS--Prevents exposed zygotes from desiccation. A major component of the cell walls of spores and pollen of many plants. Advantages of land life - ANS--More sunlight, carbon dioxide, and nutrients. Fewer herbivores and parasites, especially 425 million years ago. Disadvantages of land life - ANS--Scarcity of water. Desiccation. Gravity and lack of structural support. Differences between charophytes and land plants - ANS--1. Alternation of generations. 2. Multicellular, dependent embryos. 3. Walled spores produced in sporangia. 4. Multicellular gametangia. 5. Apical meristems. Alternation of generations in land plants - ANS--1. Gametophyte produces haploid gametes by mitosis. 2. Two gametes unite - fertilization - and form a diploid zygote. 3. Zygote develops into multicellular diploid sporophyte. 4. Sporophyte produces unicellular haploid spores by meiosis. 5. Spores develop into multicellular haploid gametophytes. Gametangia - ANS--Multicellular organs where gametes produced. Female: archegonia. Male: antheridia. Sporangia - ANS--Multicellular organisms where sporophyte produces spores. Diploid sporocytes generate haploid spores through meiosis. Apical Meristems - ANS--Localized regions of cell division at tips of roots and shoots. This sustains continues growth and allows cells to differentiate into various tissues and organs. Cuticle - ANS--Made of wax and other polymers. Covers epidermis and prevents desiccation and provides resistance to microbial attack. Fungi-Plant Interaction - ANS--420 mya first fossils of mycorrhizae and plant interaction. Allowed plants to absorb nutrients and water from soil before root systems. Plant timeline - ANS--475 mya: first fossilized land plants with spores grouped together. 425 mya: first vascular plants. 305 mya: first seeded plants. Seed - ANS--An embryo and nutrients surrounded by a protective coat. Bryophytes - ANS--First land plants. Nonvascular including: Liverworts - Hepatophyta. Mosses - Bryophyta. Hornworts - Anthocerophyta. Bryophyte Life Cycle - ANS--1. Spores develop into threadlike protonemata. 2. Haploid protonemata produce buds that divide by mitosis and grow into gametophores - male and female gametophytes. 3. Sperm from antheridia swims through film of moisture to reach egg in archegonia. 4. Zygote develops into sporophyte embryo. 5. Sporophyte grows a long stalk - seta - that emerges from archegonium. 6. Attached by its foot, the diploid sporophyte remains nutritionally dependent on the gametophyte. 7. Meiosis occurs and haploid spores develop in capsule and are then released. Nonvascular gametophyte morphology - ANS--Height constrained by lack of vascular tissue. Forms ground-hugging carpet with rhizoids anchoring it to substrate. Nonvascular sporophyte morphology - ANS--Grow from archegonia and consist of foot, seta, sporangium (capsule). Peristome discharges spores. Moss Importance - ANS--Peat moss covers 3% of earth's surface and contains 30% soil CO2. Overharvesting could greatly contribute to global warming. Seedless vascular plants - ANS--Flagellated sperm, restricted to moist environments, have no roots. Competition for space and light drove their evolution. Branching opened the way for more complex body parts. First vascular plants were only 15cm tall. Include Lycophytes and Pterophytes. Lycophytes - ANS--Seedless vascular plant that grows mainly in tropical regions. Includes club mosses, spike mosses, and quillworts. Pterophytes - ANS--Seedless vascular plants. Include ferns, horsetails, and whisk ferns. Seedless Vascular plant life cycles - ANS--1. Sporangia release spores that develop into bisexual photosynthetic gametophyte. 2. Gametophyte develops antheridia and archegonia capable of cross-fertilization or self-fertilization. 3. Sperm use flagella to swim to archegonia. 4. Zygote develops into new sporophyte from archegonium. 5. Sori - clusters of sporangia - develop on underside of sporophyte's leaves. Vascular Tissue - ANS--Allowed plants to grow tall and transport water and nutrients between distant roots and shoots. Tall plants were able to shade out competition and disperse their spores over long distances. Xylem and phloem. Xylem - ANS--Conducts most of the water and minerals. Phloem - ANS--Consists of living cells and distributes organic products. Tracheids - ANS--In xylem of most vascular plants. A tube-shaped structure that carries water and minerals up from the roots and is made of dead cells. Lignin - ANS--A polymer that strengthens the cell walls of water-conducting cells. Root evolution - ANS--Evolved from subterranean stems. Provided stability and anchored tall stems. Enabled absorption of water and nutrients from soil. Leaf evolution - ANS--Increased the surface area of vascular plants enabling them to capture more solar energy. Microphylls and megaphylls. Microphylls - ANS--Leaves with a single vein that evolved from the outgrowths of stems. Megaphylls - ANS--Leaves with branched vascular system that evolved webbing between flattened branches. Sporophylls - ANS--Modified leaves with sporangia. Sori - ANS--Clusters of sporangia on underside of sporophylls. Strobili - ANS--Cone-like structures formed from groups of sporophylls. Homosporous - ANS--Plants that produce one type of spore that develops into a bisexual gametophye. Most seedless vascular plants. Heterosporous - ANS--Plants that produce two types of spores. Megasporangium produce megaspores and microsporangium produce microspores. Significance of Seedless Vascular Plants - ANS--They grew to great heights during Devonian and Carboniferous periods forming forests. They removed CO2 from the atmosphere, contributing to global cooling at end of Carboniferous period. Decaying plants of forest became coal and other CO2 deposits. Caulerpa taxifolia - ANS--Also known as killer algae. Very invasive species; herbivores have no resistance to its toxins.