Biology Exam Review: Ch. 19-22 - Microbes, Protists, Fungi, Plants, Animals - Prof. C. Ras, Study notes of Biology

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Biology Exam #2 Chapter 19  Bacteria and Archae are fundamentally different  Entirely prokaryotes  Biochemical features:  Bacteria contains peptidoglycan in the cell wall  Archae have hydrocarbons in the cell wall  They also differ in the plasma membranes, ribosomes, and RNA polymerase  Classification in Prokaryotes  Small and simple  Classified by: shape, locomotion, pigments, nutrient requirements, appearance of colonies, and staining properties  Comparative DNA and RNA nucleotide sequences  Prokaryotes differ in size and in shape  Bacteria are larger, and cell walls change shape (Spherical, rodlike, and corkscrew)  Survival and reproduction  Motile prokaryotes have flagella (long hairlike structures that help movement)  Wheel like in membrane, thin protein  Many bacteria form film on surfaces  Sporulation creates and endospore (genetic material and enzymes encased in a protective coat) for survival in harsh conditions  Can form a protective slime made of polysacharrides(protein), to protect cells and helps them stick  Biofilm – aggregate in colonies to form communities ex- plaque  Some prokaryotes are anaerobic (live without oxygen)  Reproduce by binary fission (process in which a single celled organism divides in half producing two identical offspring)  Conjugation – transfer of DNA from one cell to another via a temporary connection  Impact on humans and other organisms  Play important roles in animal nutrition – digestive tracts  Nitrogen fixing bacteria (remove nitrogen from the atmosphere and combine it with hydrogen to produce ammonium) capture nitrogen needed by plants  Some threaten human health  Pathogenic (disease causing)  some produce poisin  humans constantly battle new and old bacteria  common bacteria can be harmful  Viruses, Viroids and Prions  Virus consists of a molecule of DNA or RNA surrounded by a protein coat multiply within a host  Viruses are parasites  Host specific  Infectious, difficult to treat  Bacetriophage – virus that only infects bacteria  Viroids (a particle of RNA that is capable of infecting a cell and directing the production of more viroids – plant diseases)and Prions (a protein that in mutated forms acts as an infectious agent that causes certain neurodegenerative disease – Kuru and Scrapie)are smaller than viruses Chapter 20  Protists  Single celled, not an animal plant or fungi  Modes of Nutrition  free living or parasitic  Heterotrphic use of psuedopds (finger like extensions to engulf prey)  Food vacuoles  Either, ingest, absorb, or use photosynthesis  Reproduction  Sexual and Asexual (mitotic)methods  Micronuclei and Conjugation  Affect on humans and other organisms  Make energy available to others  Cause disease and release toxins  Major groups of protists 1. Excavates  Lack mitochondria and nuclei  Feeding groove a) Diplomonads – have two nuclei and move by flagella b) Parabasalids – mutualists and parasites (anaerobic flagellated protists) live inside animals 2. Egleozoans  Distinctive mitochondria a) Euglenids – lack a rigid covering and swim by flagella (single celled protists in fresh water) b) Kinetoplastids – cause human disease, mitochondria DNA is arranged in kinetoplasts (stacks of disks) 3. Stramenopiles  Photosynthetic and non photosynthetic  Genetically classified  Hairlike flagella Chapter 22  Key features of fungi o Composed of Hyphae(filamentous threads – multicellular or multinucleated) that forms and interwoven mass mycelium o Chitin cell wall and are haploid o Heterotrophic – secrete enzymes to break down nutrients – decomposers, parasites, predators, and mutualistic o Propogate by Spores(haploid reproductive cells capable of developing into adults)  Sexually – meiotic  #1 Asexually – Mitotic  Major Groups 1. Chytrids – a. Live in water – required for reproduction b. Haploid or diploid flagellated spores c. Septa are absent d. Decline of frog populations 2. Zygomycetes – a. Soil or decaying material b. Diploid sexual zygospores c. Black bread mold and soft fruit rot 3. Glomeromycetes a. Roots of plants b. Haploid asexual spores (clusters) c. Septa are absent d. Form mycorrhizae(plant root) 4. Basidiomycetes a. Underground b. Reproduce sexually – produce club shaped reproductive structures called basidia c. Septa are present d. Mushrooms, smuts, and rusts on crops 5. Ascomycetes a. Largest group b. Haploid sexual acospores in saclike ascus c. Septa are present d. Molds, yeasts, and can live in decaying forest vegetation  Interactions with other species o Lichens – symbiotic between fungus and algae (protects algae and lichens receive sugars) o Michorrhizae – symbiotic between fungi and plant roots(helps feed plants and invade land and fungi receives sugars) o Endophytes – symbiotic between the inside of plant stems and leaves(keep herbivores away and feeds fungi) o Saphrophytes – decompose dead organisms  Affect on humans o Attacks plants important to humans o Cause human disease and produce toxins o Atibiotics from fungi o Gastronomy o Yeast- beer, wine, and bread rise Chapter 23  Key Features of animals 1. Multicellular 2. Lack cell walls 3. Heterotrophic 4. Sexual reproduction 5. Motile 6. Respond to stimuli  Anatomical Features o Lack of tissues in sponges separate them from all other animals o Symmetry 1. Bilateral – 3 embryonic germ layers (endoderm, ectoderm, and mesoderm)  Typically have cephalization and some type of body cavity (have heads_ o Protostome- develop a body cavity within the body wall (annelids, mollusks, and arthropods)  Have two distinct evolutionary lines 1. Ecdysozoans 2. iophotrochozoans o Duterostome – develop a body cavity as an outgrowth of the digestive cavity (echinoderms and chordates) 2. Radial – 2 embryonic germ layers  Major Animal Phyla 1. Sponges  Simple body plan  Reproduce by budding, and sexually  Lack tissues  Specialized cells for diff functions 2. Cnidarians (jellyfish, sea anemones, corals, and hydrozoans)  Polyp and Medusa forms  Possess tissues with radial symmetry  Stinging cnidocytes  Simple nervous system  Central gastrovascular cavity  Many corals secrete hard skeletons 3. Platyhelminthes (flatworms)  Parasitic or free living  Cephalization = bilateral symmetry  Lack a body cavity , respitory and circulatory (too flat)  Gas exchange by diffusion 4. Annelids (Segmented worm – oligochaetes, polychaetes, and leeches)  Coelmates and have organ systems o A coelom is filled with fluid and provides a hydrostatic skeleton  Closed circulatory system  Nephridia – excretory organs filter and remove wastes 5. Mollusks (snails, clams, and squid)  Soft bodies protected by some kind of shell  Gills and annelid like nervous system  Open circulatory system  Gastropods, bivalves(filter feeders), and cephalopods 6. Arthropods – most diverse  Have appendages and external skeleton  Specialized segments and adaptions  Gills, trachea, or lungs for gas exchange  Open circulatory system  Some insects can fly  Arachnids are predatory meat eaters  Myriapods have many legs (50, 70, 90)  Crustaceans are aquatic 7. Nematoda or Roundworms – abundant and mostly tiny  Pseudocoelmates with a simplified body plan  Reproduce sexually  Lack circulatory and respitory systems 8. Echinodermata - calcium carbonateskeleton  Bilaterally symmetrical as larvae  Radial symmetry as adults  Water vascular system 9. Chordates – include vertebrates Chapter 24