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Prokaryotes and viruses Prokaryotes Eubacteria (true bacteria) Archaebacteria (Ancient Bacteria) No organelles with double membrane NUCLEOID with a single circular chromosome Accessory rings of DNA called PLASMIDS binary transverse fission and budding In the budding bacteria Hyphomonas polymorpha, the bud grows out of the end of a filament called a prostheca. Most bacteria reproduce by a process of binary transverse fission Sporulation – endospores in Bacillus and Clostridium – cysts in Azotobacter – heterocysts in some cyanobacteria. Bacterial gene exchange pilus CONJUGATION (exchange of DNA) TRANSFORMATION- bacteria incorporate genes from dead bacteria TRANSDUCTION - viruses insert new genes into bacterial cells Inclusions Inclusions are reserve deposits found in prokaryotic and eukaryotic cells. • • • • • inorganic phosphate polysaccharide granules lipids reserve carbon gas vacuoles (cyanobacteria) Acidocalcisomes Organelles rich in calcium and polyphosphate described in several parasites, algae, and slime molds. • Main Func)ons: • calcium homeostasis • maintenance of intracellular pH • osmoregulation. Acidocalcisomes Agrobacterium tumefaciens have flagella Soil à rhizosphere. carries the distinct Ri (rootinducing) plasmid. Acidocalcisomes Agrobacterium tumefaciens attacks a broad spectrum of woody and herbaceous plants Euonymoum Brambles Grape Maple Rose Willow Cyanobacteria the blue-green algae Photosynthetic Chlorophyll a Phycobilins – Phycocyanin – Phycoerithrin Thylacoids Glycogen Cyanobacteria the blue-green algae Each cell is individual Joined by walls or mucilaginous sheaths Cyanobacteria the blue-green algae Specialized cells Necridia Hormogonia Cyanobacteria the blue-green algae Akinetes • Asexual propagules derived from vegetative cells. • No photosynthetic • Contain cyanophycin granules (Amino Acids) and lipids • N è ammonium (NH4+) Symbiotic associations Azolla (fern) + Anabaena azollae (cyanobacteria). The algal symbiont resides in the leaf cavity of Azolla in exchange for nutrients and carbon sources. Rhizobium Soil bacteria that fix nitrogen Endosymbiotic association with legumes root nodules Spiroplasma No cell walls Can assume various forms Spiroplasma citri causes stubborn disease in grapefruit and sweet oranges Phytoplasm They are mycoplasma-like organisms Parasites Passive or active Attack the sieve tube elements in the phloem Transmitted from plant to plant by insects Pseudomonas Xanthomonas Viruses § Obligate intracellular parasites of • Plants • Animals • Fungi • Bacteria § protein coat § nucleic acid core DNA or RNA § They cannot carry out metabolism Plant viruses 600 kinds of plant viruses 2000 plant diseases Common symptoms: Chlorotic or necrotic tissues Plant viruses DNA viruses Geminiviruses (groups of two) Badnaviruses (Bananas) Caulimoviruses (Cauliflower) Transmission from plant to plant Vectors with piercing and sucking mouthparts wounds From infected pollen to the ovule Inside the plant via plasmodesmata Phloem Movement proteins Attendance Viruses are obligated intracellular parasites True False What is the difference between a pilus and a bacterial flagellum? Explain the differences between binary fission and budding in bacteria Define plasmid, heterocysts , necridia What is the function of Inclusions in bacteria? What is the effect of spiroplasmas in plants meristem? Mentin all the different ways that bacteia can reproduce
