Amoeba proteus - MDC Faculty Home Pages
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Amoeba proteus - MDC Faculty Home Pages
Amoeba proteus Amoeba proteus, previously Chaos diffluens, is an amoeba closely related to the giant amoebae. This small PROTOZOAN uses tentacular protuberances called PSEUDOPODIA to move and phagocytosize smaller unicellular organisms, which are enveloped inside the cell's cytoplasm in a food vacuole,[1] where they are slowly broken down by enzymes. Amoeba proteus is very wellknown for its extending pseudopodia. A. proteus possesses a nucleus containing granular chromatin, and is therefore a EUKARYOTE. Anabaena Anabaena is a genus of filamentous cyanobacteria, or blue-green algae, found as plankton. It is known for its nitrogen fixing abilities, and they form symbiotic relationships with certain plants, such as the mosquito fern. They are one of four genera of cyanobacteria that produce neurotoxins, which are harmful to local wildlife, as well as farm animals and pets. Production of these neurotoxins is assumed to be an input into its symbiotic relationships, protecting the plant from grazing pressure. Aspergillus conidiophore Mold (Aspergillus) Conidiophores As one of the two common genera of molds on fruits and other foods such as grain, wheat, and bread, species of the genus Aspergillus are distinguished from Penicillium species by the origin of their spore-bearing stalks or conidiophores. In Aspergillus, the conidiophore arises from a foot-cell, a vegetative mycelium. Bacterial nucleoplasm Bacteria nucleoplasm The protoplasm of a cell nucleus. Coprinus mushroom The genus Coprinus is a small genus of mushrooms consisting of Coprinus comatus (the shaggy mane) and several of its close relatives. Until 2001, Coprinus was a large genus consisting of all agaric species in which the lamellae autodigested to release their spores. (The black ink-like liquid this would create gave these species their common name "inky cap".) Molecular phylogenetic investigation found that Coprinus comatus was only a distant relative of the other members of Coprinus, and was closer to genera in the Agaricaceae. Since Coprinus comatus is the type species of Coprinus, only that species and its close relatives C. sterquilinus and C. spadiceisporus retained the name of the genus The majority of species of Coprinus were therefore reclassified into the genera Coprinellus, Coprinopsis, and Parasola.Coprinus and these segregate genera are now referred to collectively as coprinoid fungi. Euglena Euglena is a genus of unicellular protists, of the class Euglenoidea of the phylum Euglenophyta, also known as Euglenozoans. They are single-celled organisms. Currently, over 1000 species of Euglena have been described. Marin et al. (2003) revised the genus to include several species without chloroplasts, formerly classified as Astasia and Khawkinea. Some Euglena are considered to have both plant and animal features. Due to these dual characteristics, much debate has arisen to how they have evolved, and into which clade they should be placed. Euglenas were originally placed in the kingdom Protista but now are classisfied above the kingdom Euglenozoa, which contains both Kinetoplastids and Euglenids. A Euglena is a protist that can both eat food as animals by heterotrophy; and can photosynthesize, like plants, by autotrophy. When acting as a heterotroph, the Euglena surrounds a particle of food and consumes it by phagocytosis. When acting as an autotroph, the Euglena utilizes chloroplasts, containing Chlorophyll A, Chlorophyll B, and some carotenoid pigments, to produce sugars by photosynthesis. Euglenas are able to move through aquatic environments by using a large, rear mounted flagellum for locomotion. Euglenas reproduce asexually by fission, and there has been no existence of sexual reproduction. Fucus male conceptacle Fucus, better known as kelp or seaweed, is a genus of exclusively-marine brown macroalgae in the family Phaeophyceae. The phytopigment fucoxanthin masks the natural green of the chlorophylls in these multicellular intertidal and subtidal plants. Known also as wracks, the Fucus brown seaweeds are always diploid and meiosis takes place before the gametes are formed. The reproductive organs of the macroalgae consist of receptacles and conceptacles. Gamete production takes place in specialized crypt-like structures known as conceptacles. The conceptacles are carried in receptacles, which are swollen areas found at the tips of the plants. While some species of wracks are dioecious, others feature both types of sexual organs on one plant and are classified as monoecious. To add to the diversity of reproductive strategy featured by this genus of brown algae, some of the monoecious species have both sexes in a single conceptacle while others contain them in separate organs. The conceptacles for the male reproductive organs are lined with antheridiophores, which are branched and feature inflated, terminal antheridia on their branches. The antheridia are the sites of meiosis, forming 64 to 128 biflagellated male gametes that are referred to as antherozoids. The male and female gametes are usually released into the water during a rising tide with the female eggs emitting a potent volatile hydrocarbon compound (fucoserraten), which acts as an attractant for the mobile male antherozoids. The fertilized egg settles onto the sediment and germinates as a new diploid thallus. fucus monoecious conceptacles Fucus is a genus of brown alga in the Class Phaeophyceae to be found in the intertidal zones of rocky seashores almost everywhere in the world. Known also as wracks, the Fucus brown seaweeds are always diploid and meiosis takes place before the gametes are formed. The reproductive organs of the macroalgae consist of receptacles and conceptacles. Gamete production takes place in specialized crypt-like structures known as conceptacles. The conceptacles are carried in receptacles, which are swollen areas found at the tips of the plants Mixed diatom Diatoms (Greek: διά (dia) = "through" + τέμνειν (temnein) = "to cut", i.e., "cut in half") are a major group of eukaryotic algae, and are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons (e.g. Fragillaria), fans (Meridion), zigzags (Tabellaria), or stellate colonies (Asterionella). Diatoms are producers within the food chain. A characteristic feature of diatom cells is that they are encased within a unique cell wall made of silica (hydrated silicon dioxide) called a frustule. Oscillatoria Oscillatoria is a genus of filamentous cyanobacteria which is named for the oscillation in its movement. Filaments in the colonies can slide back and forth against each other until the whole mass is reoriented to its light source. It is commonly found in wateringtroughs waters, and is mainly blue-green or brown-green. Oscillatoria is an organism that reproduces by fragmentation. Oscillatoria forms long filaments of cells which can break into fragments called hormogonia. The hormogonia can grow into a new, longer filament. Breaks in the filament usually occur where dead cells(necridia) are present. Oscillatoria uses photosynthesis to survive and reproduce. Paramecium Paramecia, also known as Lady Slippers, due to their appearance, are a group of unicellular ciliate protozoa, which are commonly studied as a representative of the ciliate group, and range from about 50 to 350 μm in length. Simple cilia cover the body, which allow the cell to move with a synchronous motion (like a caterpillar). There is also a deep oral groove containing inconspicuous compound oral cilia (as found in other peniculids) used to draw food inside. They generally feed on bacteria and other small cells. Osmoregulation is carried out by a pair of contractile vacuoles, which actively expel water from the cell absorbed by osmosis from their surroundings. Paramecia are widespread in freshwater environments, and are especially common in scums. Certain single-celled eukaryotes, such as Paramecium, are examples for exceptions to the universality of the genetic code (translation systems where a few codons differ from the standard ones). Penicillium Penicillium (from Latin penicillus: paintbrush) is a genus of ascomycetous fungi of major importance in the environment, food and drug production. The thallus , (mycelium) typically consists of a highly branched network of multinucleate, septate, usually colorless hyphae. Many-branched conidiophores sprout on the mycelia, bearing individually constricted conidiospores. The conidiospores, are the main dispersal route of the fungi, and often green. Sexual reproduction involves the production of ascospores, commencing with the fusion of an ascogonium and an antheridium, with sharing of nuclei. The irrregularly distributed asci contain eight unicellular ascospores each. Peridinium Peridinium is a dinoflagellate with thick, armored plates that are often lobed and ornamented. The sutures are quite noticeable, and the cingulum is nearly at the cell median. The cells may be generally round to oval-shaped or flattened, with a convex dorsal surface and a concave ventral surface. Some species (such as Peridinium limbatum) have distinctive horns. The genus has over 30 species, most of which are photosynthetic. Physarum plasmodium Physarum plasmodiumbelongs to the supergroup Amoebozoa, phylum Mycetozoa, and class Myxogastria. P. polycephalum, often referred to as the “many-headed slime,” is a slime mold that inhabits shady, cool, moist areas, such as decaying leaves and logs. This protist may be seen without a microscope; P. polycephalum is typically yellow in color, and eats fungal spores, bacteria, and other microbes. P. polycephalum is one of the easiest eukaryotic microbes to grow in culture, and has been used as a model organism for many studies involving amoeboid movement and cell motility. Most organisms receive mitochondrial DNA from their mother, but it is not known from where P. polycephalum receives its mitochondrial DNA as it is currently not possible to distinguish between male and female. Saccharomyces budding cells The yeast open species Saccharomyces cerevisiae has been used in baking and fermenting alcoholic beverages for thousands of years. It is also extremely important as a model organism in modern cell biology research, and is one of the most thoroughly researched eukaryotic microorganisms. Researchers have used it to gather information about the biology of the eukaryotic cell and ultimately human biology. Other species of yeast, such as Candida albicans, are opportunistic pathogens and can cause infections in humans. Yeasts have recently been used to generate electricity in microbial fuel cells,and produce ethanol for the biofuel industry. Saprolegnia Saprolegnia is a genus of freshwater mould often called a "cotton mould" because of the characteristic white or grey fibrous patches it forms. Current taxonomy puts Saprolegnia as a genus of the heterokonts in the order Saprolegniales. Saprolegnia is tolerant to a wide range of temperature, 3°C to 33°C, but is more prevalent in lower temperatures. While it is found most frequently in freshwater, it will also tolerate brackish water and even moist soil. Saprolegnia filaments (hyphae) are long with rounded ends, containing the zoospores. Saprolegnia generally travels in colonies consisting of one or more species. They first form a mass of individual hyphae. When the mass of hyphae grows large enough in size to be seen without use of a microscope, it can be called a mycelium. Colonies are generally white in color, though they may turn grey under the precesence of bacteria or other debris which has become caught in the fibrous mass. Rhizopus sporangia Rhizopus is a genus of molds that includes cosmopolitan filamentous fungi found in soil, decaying fruit and vegetables, animal faeces, and old bread. Rhizopus species produce both asexual and sexual spores. The asexual sporangiospores are produced inside a pinhead-like structure, the sporangium, and are genetically identical to their parent. In Rhizopus, the sporangia are supported by a large apophysate columella, and the sporangiophores arise among distinctive rhizoids. Dark zygospores are produced after two compatible mycelia fuse during sexual reproduction. They give rise to colonies that may be genetically different from their parents. Some Rhizopus species are opportunistic agents of human zygomycosis. They may cause serious (and often fatal) infections in humans and animals because of their rapid growth rate and growth at relatively high temperatures. Spirogyra Spirogyra is a genus of filamentous green algae of the order Zygnematales, named for the helical or spiral arrangement of the chloroplasts that is diagnostic of the genus. It is commonly found in freshwater areas, and there are more than 400 species of Spirogyra in the world. Spirogyra measures approximately 10 to 100μm in width and may stretch centimeters long. Spirogyra is unbranched with cylindrical cells connected end to end in long green filaments. The cell wall has two layers: the outer wall is composed of cellulose while the inner wall is of pectin. The cytoplasm forms a thin lining between the cell wall and the large vacuole it surrounds. Chloroplasts are embedded in the peripheral cytoplasm; their numbers are variable (as few as one). The chloroplasts are ribbon shaped, serrated or scalloped, and spirally arranged, resulting in the prominent and characteristic green spiral on each filament. Each chloroplast contains several pyrenoids, centers for the production of starches, appearing as small round bodies. Stemonitis Stemonitis is a distinctive genus of slime molds found throughout the world (except Antarctica). They are characterised by the tall brown sporangia, supported on slender stalks, which grow in clusters on rotting wood. Identification within the genus is difficult, and can only be performed with confidence using a microscope.