The attachments are evolution lab questions and the answer sheet to answer the questions
Assignment: Turn in the following table and the six questions on Black board. Type all of your answers and use 14 point type. Use the outlines provided to write your answers. This means the outline topics should be the headings of your answers. If you do not do this you will suffer a five-point penalty per question. Remember that this Lab is checked with Safe Assign. If you copy and paste you will be given a zero. Short answers from Lab Exercise. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. Table 1. Characteristics of Studied Plant Divisions Use a large + sign (20 point) if present. Leave blank if not present.- 5 points if you do not follow these directions. Character Bryophyta Pterophyta (Ferns) Coniferophyta (Conifers) Anthophyta (Flowering Plants) Cuticle Only Rhizoids Vascular tissue Only Rhizomes Flagellated sperm Separate male and female gametophytes Parasitic or non-photosynthetic sporophytes Photosynthetic gametophytes and sporophytes Parasitic or non-photosynthetic sporophyte Air borne spores Pollen Embryo protected by seed coat Seeds within fruit Lab Summary questions Use your own words to answer these questions. Don’t copy directly from the lab exercise or any other document. Give detailed answers and be specific. Each question should be a couple of paragraphs or more. Include the questions with your answers (-5 points if you don’t) 1. Describe the evolution of multicellularity illustrated by species within Chlorophyta. Include a discussion of: isogamy/ heterogamy; colonial/ multicellular; alternation of generation. Use the outline below and discuss each issue for each example. Chlamydomonas Pandorina Volvox Ulva 2. Describe sexual reproduction in a moss. Don’t include asexual reproduction. What generation does sexual reproduction occur in? What process of division produces the gametes? Description of plant and structure of gametangium Production of Gametes Fertilization Development of next Generation 3. Describe asexual (spore formation) and sexual reproduction in a fern. Start with the germination of a spore. . Use the outline below Germination of spore and development of next generation Description of plant and structure of gametangium Production of Gametes Fertilization Development of next Generation Description of plant and structure of reproductive organs Spore Production 4. Describe reproduction in a pine. Begin with descriptions of how the male and female gametophytes are formed. Give details of structure. Use the outline below. . Use the outline below Formation of Male Gametophytes (Male cone, Gametagangium, Production of Gametophyte) Formation of Female Gametophytes (Female cone, Gametagangium, Production of Gametophyte) Fertilization Seed Development 5. Define gametophyte and sporophyte. Give brief descriptions of each in mosses, ferns, pines and flowering plants (You don’t have to describe how the gametophytes are formed only what they are.). Use the outline below in answering this question. Definition of gametophyte: Moss gametophyte Fern gametophyte Pine gametophyte Flowering Plant gametophyte Definition of sporophyte: Moss sporophyte Fern sporophyte Pine sporophyte Flowering Plant sporophyte 6. Describe the various adaptations to the terrestrial environment that you observed in bryophytes, ferns, pines, and to a lesser extent in flowering plants. Use the outline below in answering this question. Adaptations: Bryophytes Ferns Pines Flowering plants. BS4440 Evolution BS4440 Evolution Evolution Laboratory 7 Plant Phylogeny 1 Objectives 1. To observe the development of complexity of organization in algae. 2. To examine morphological structures in mosses, ferns, conifers, and flowering plants 3. To recognize the adaptations to a terrestrial existence 4. To learn the life cycle stages in the alternation of generations found in mosses, ferns, gymnosperms, and angiosperms This is a log exercise and you should a lot as much time as you would spend in the lab (2 1/2 hours). This lab will substitute videos and Micrographs for viewing specimens under the microscope and dissections. Please access the videos and then answer the questions about your observations. Origin of plants from Algae Blue green Algae or Cyanobactera The origin of eukaryotic plants from prokaryotes is thought to involve the endosymbiotic incorporation of cyanobacteria into some larger cell as a chloroplast. Cyanobactera are thought to be responsible for changing the atmosphere from a reducing environment to an oxidizing one. They are also thought to have created the stromatolites characteristic of the early Paleozooic era. Make a wet mount of Anabaena, a filamentous cyanobacterium. Use the India ink method to see the gelatinous sheath. Along the filament, you should be able to see some cells that are differentiated. Elongated cells with thick cell walls are akinetes (spores). Enlarged but somewhat spherical cells are heterocysts, which have the enzymes for fixing atmospheric nitrogen. They will be most common in cells coming from growth media that are low in nitrate or nitrogen- containing organic compounds. The thick walls of these cells are thought to have evolved in response to the rising oxygen levels in the Paleozooic era that would interfered with nitrogen fixation. Sketch a filament of Anabaena below and include examples of all three types of cells. https://www.youtube.com/watch?v=HKX42psLc0k https://www.youtube.com/watch?v=pFsty-XyLZc Compare the anabaena with chloroplasts from a wet mount of an Elodea leaf. 1. Are they of a similar size and appearance? Examine a specimen of a stromatolite under the dissecting microscope. 2. What features of this fossil indicate it was formed from a matt of blue green algae? https://fr.coursera.org/lecture/our-earth/video-4-3-2-the-earliest-life-on-earth-QonUn Phylum Chlorophyta, the green algae The 7,000 or so species of green algae can be grouped to create a natural progression from single cells to multicellularity. Three lines of evolution are apparent: (1) the formation of colonies; (2) the formation of multicellular filaments; and (3) the formation of definite multicellular organisms. Colonial Series You will examine species from three genera collectively called the volvocine series: Chlamydomonas, Pandorina, and Volvox. View Chlamydomonas at different magnifications. Note that they are much larger than anabaena and possess chloroplasts https://www.youtube.com/watch?v=cFfiCzKV9-k Under favorable conditions of light intensity, temperature, nitrogen starvation, or attach by bacteria Chlamydomonas will undergo sexual reproduction. Cells fuse and produce a zygote that becomes a cyst for long term survival. Watch the video of Chlamydomonas fusing while under attack by bacteria. Cells that fuse are different mating types designated + or -. Go to the video at this web site entitled C. reinhardtii surrounded by the harmful bacteria Pseudomonas protegens https://elifesciences.org/articles/39233/figures Compare what you have seem to the life cycle in figure below. Chlamydomonas is capable of asexual and sexual reproduction. In asexual reproduction, the cells divide by mitosis. In the initial stages of sexual reproduction, such as you just observed, cells of different mating types come together and their flagella intertwine. The cells are gametes and fuse to produce a zygote. Because the two mating types are morphologically identical, Chlamydomonas is described as being isogamous (having identical male and female gametes). The zygote will eventually develop a thick wall and go into a period of dormancy, usually over winter. When dormancy ends, the zygote will divide by meiosis to produce four cells (zygospores), which will become typical adult cells. 3. Is an adult cell of Chlamydomonas haploid or diploid? 4. What about the zygote? Pandorina is an algae similar to Chlamydomonas in appearance that forms a small colony in a gelatinous matrix. This loose association is perhaps the first step toward multicellularity. Draw a picture of Pandorina in the circle below. Watch the video of Pandorina. https://www.youtube.com/watch?v=CkDxG4p6yBU Now watch the video of Volvox. https://www.youtube.com/watch?v=n7RggKhWD8g 5. How does Volvox differ from Chiamydomonas and Pandorina? 6. How is it similar? A colony of Volvox consists of 500 to 50,000 cells. The coordinated stroking of two flagella in each cell allows the organism to move in a direction while spinning on its axis. The cells in the colony are held together by a gelatinous matrix and are connected to neighboring cells by thin strands of protoplasm. Young colonies produced by either asexual or sexual reproduction may be contained inside the parent colony (figure below). In sexual reproduction, several cells in the colony differentiate into motile sperm and a few others become nonmotile eggs. Sperm swim to the eggs, and fuse with them to form zygotes. Zygotes undergo meiosis and develop into haploid daughter colonies inside the parent colony and are released when it dies. Because the male and female gametes can be distinguished from one another, Volvox is described as being heterogamous (having different male and female gametes). Oogamous organisms such as Volvox have large, nonmotile eggs. The cells that produce sperm are called antheridia, and those that produce eggs are called oogonia. Because of this differentiation of cell types and division of labor, the colony has some of the properties of a truly multicellular organism. Leafy Series Watch the video of Ulva the sea lettuce (figure below). https://www.youtube.com/watch?v=TO9vnUc4DIY It typifies another line of evolution among the green algae. The leaf like body of this algae, the thallus, is multicellular and is only two cells thick. Some of the cells at the base are modified into a holdfast, which anchors the thallus in place against tidal currents. 7. What might these structures be pre-adaptations for in vascular plants? If the number of chromosomes in mature individual Ulva are counted, some individuals are diploid and others haploid. The diploid individuals result from the formation of a zygote by the fusion of isogametes. The isogametes are formed by the haploid individuals. Haploid individuals grow from zoospores, motile cells produced by meiosis of cells in the diploid individuals. Thus, Ulva shows a clear-cut pattern of alternation of generations. The diploid individuals represent the sporophyte generation and the haploid individuals are called gametophytes. Origins of Land Plants Plants are a diverse group of multicellular, photosynthetic organisms ranging from simple mosses to complex flowering plants. All plants, and some green algae, share certain characteristics, which include: (1) chloroplasts with thylakoid membranes stacked as grana and containing chlorophylls a and b, (2) starch as a storage polysaccharide in the chloroplasts, (3) cellulose in cell walls, (4) cytoplasmic division by cell plate (phragmoplast) formation, and (5) complex life cycles involving an alternation of generations in which a diploid sporophyte stage alternates with a haploid gametophyte stage. While it is customary to include the algae in courses dealing with botany, they are now considered protistans and not plants. Botanists prefer to