|
Chlainomonas
''Chlainomonas'' is a genus of algae in the family Chlamydomonadaceae.See the NCBIbr>webpage on Chlainomonas Data extracted from the They are found in freshwater habitats or on snow, where they are one of the main algae responsible for causing watermelon snow. Description ''Chlainomonas'' consists of single, ovate cells with four apical flagella attached at the tip. The protoplast is separated from the cell wall by a thick, hyaline layer; it is often filled with red pigments. There is a single chloroplast filling the cell. Pyrenoids are absent, or may be otherwise difficult to observe within the cytoplasm. There are typically two contractile vacuoles at the apex of the cell. Some species have a stigma. Life cycle ''Chlainomonas'' reproduces asexually; no sexual reproduction has been observed in this genus. The mode of asexual reproduction in ''Chlainomonas'' is highly unusual. During ''Chlainomonas'', new cells are produced when the protoplasm is squeezed through the cell en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlainomonas Kolii
''Chlainomonas'' is a genus of algae in the family Chlamydomonadaceae.See the NCBIbr>webpage on Chlainomonas Data extracted from the They are found in freshwater habitats or on snow, where they are one of the main algae responsible for causing watermelon snow. Description ''Chlainomonas'' consists of single, ovate cells with four apical flagella attached at the tip. The protoplast is separated from the cell wall by a thick, hyaline layer; it is often filled with red pigments. There is a single chloroplast filling the cell. Pyrenoids are absent, or may be otherwise difficult to observe within the cytoplasm. There are typically two contractile vacuoles at the apex of the cell. Some species have a stigma. Life cycle ''Chlainomonas'' reproduces asexually; no sexual reproduction has been observed in this genus. The mode of asexual reproduction in ''Chlainomonas'' is highly unusual. During ''Chlainomonas'', new cells are produced when the protoplasm is squeezed through the cell env ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlamydomonadaceae
Chlamydomonadaceae is a family of algae within the order Chlamydomonadales. Traditionally, it has been defined as containing single-celled flagellates with a cell wall. Cells of the Chlamydomonadaceae are motile and have one, two, or four flagella. The cell body is covered in a cell wall, with the protoplast entirely or partially lined up next to the wall. Cells are uninucleate (i.e. with one nucleus). There is generally a single chloroplast, which is often cup-shaped or sometimes stellate or discoid; pyrenoids may be present or absent. Some species lack chlorophyll entirely and are saprotrophic. Contractile vacuoles may or may not be present. There is usually a single eyespot. Asexual reproduction occurs when the cell protoplast divides to form two, four, or eight daughter cells, with cell walls forming while still in the parent cell wall. Before cell division, the flagella usually disappear. Daughter cells are typically liberated when the parent cell wall gelatinizes, or th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resting Spore
A resting spore is a resistant cell, adapted to survive adverse environmental conditions. Resting spore is a term commonly applied to both diatoms and fungi. In fungi and oomycetes A resting spore can be a spore created by fungi which is thickly encysted (has a thick cell wall) in order to survive through stressful times, such as drought. It protects the spore from biotic (microbial, fungal viral), as well as abiotic (wind, heat, xeric conditions) factors. Resting spores of a particular oomycete species are important in causing late potato blight. They can lie dormant within the soil of a field for decades until the right conditions occur for viability (plant host present, rain, fire etc.). In diatoms A similar resting spore life stage is also present in diatoms, and in such case, is also often referred to as the hypnospore. Importantly, the resting spore of marine diatoms is not an obligate stage of the life cycle, except in the minority of studied taxa, where spore produ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphyletic
Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In contrast, a monophyletic grouping (a clade) includes a common ancestor and ''all'' of its descendants. The terms are commonly used in phylogenetics (a subfield of biology) and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies. If many subgroups are missing from the named group, it is said to be polyparaphyletic. The term received currency during the debates of the 1960s and 1970s accompanying the rise of cladistics, having been coined by zoologist Willi Hennig to apply to well-known taxa like Reptilia (reptiles), which is paraphyletic with respect to birds. Reptilia contains the last common ancestor of reptiles and all descendants of that ancestor exc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloromonas
''Chloromonas'' is a genus of green algae in the family Chlamydomonadaceae. It is closely related to the model green algae, ''Chlamydomonas'', and traditionally has been distinguished mainly through the absence of a pyrenoid. Species of ''Chloromonas'' occupy a variety of habitats, including soil, temporary pools of fresh water and eutrophic lakes. A number of species are adapted to living on snow, making them snow algae. The most northerly location at which this algae has been observed is Lake Bienville, Quebec, 55°N. Description ''Chloromonas'' is a unicellular organism with cells that are ranging from spherical, ovoid, cylindrical, or spindle-shaped. There are two equal flagella on the anterior end of the cell, with or without a papilla. As single large chloroplast fills the cell, and may be cup-shaped and variously lobed. Chloroplasts lack pyrenoids. An eyespot apparatus, eyespot is present in most species. There is a single nucleus typically embedded in the center of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monophyletic
In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent common ancestor (or more precisely an ancestral population), i.e. excludes non-descendants of that common ancestor # the grouping contains all the descendants of that common ancestor, without exception Monophyly is contrasted with paraphyly and polyphyly as shown in the second diagram. A ''paraphyletic'' grouping meets 1. but not 2., thus consisting of the descendants of a common ancestor, excepting one or more monophyletic subgroups. A '' polyphyletic'' grouping meets neither criterion, and instead serves to characterize convergent relationships of biological features rather than genetic relationships – for example, night-active primates, fruit trees, or aquatic insects. As such, these characteristic features of a polyphyletic grouping ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Zealand
New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of island countries, sixth-largest island country by area and lies east of Australia across the Tasman Sea and south of the islands of New Caledonia, Fiji, and Tonga. The Geography of New Zealand, country's varied topography and sharp mountain peaks, including the Southern Alps (), owe much to tectonic uplift and volcanic eruptions. Capital of New Zealand, New Zealand's capital city is Wellington, and its most populous city is Auckland. The islands of New Zealand were the last large habitable land to be settled by humans. Between about 1280 and 1350, Polynesians began to settle in the islands and subsequently developed a distinctive Māori culture. In 1642, the Dutch explorer Abel Tasman became the first European to sight and record New Zealand. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Northwest
The Pacific Northwest (PNW; ) is a geographic region in Western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though no official boundary exists, the most common conception includes the U.S. states of Oregon, Washington (state), Washington, Idaho, and the Canadian province of British Columbia. Some broader conceptions reach north into Alaska and Yukon, south into Northern California, and east into western Montana. Other conceptions may be limited to the coastal areas west of the Cascade Mountains, Cascade and Coast Mountains, Coast mountains. The Northwest Coast is the coastal region of the Pacific Northwest, and the Northwest Plateau (also commonly known as "British Columbia Interior, the Interior" in British Columbia), is the inland region. The term "Pacific Northwest" should not be confused with the Northwest Territory (also known as the Great Northwest, a historical term in the United States) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protoplast
Protoplast (), is a biology, biological term coined by Johannes von Hanstein, Hanstein in 1880 to refer to the entire cell, excluding the cell wall. Protoplasts can be generated by stripping the cell wall from plant, bacterium, bacterial, or fungus, fungal cells by mechanical, chemical or enzymatic means. Protoplasts differ from spheroplasts in that their cell wall has been completely removed. Spheroplasts retain part of their cell wall. In the case of Gram-negative bacterial spheroplasts, for example, the peptidoglycan component of the cell wall has been removed but the bacterial outer membrane, outer membrane component has not. Enzymes for the preparation of protoplasts Cell walls are made of a variety of polysaccharides. Protoplasts can be made by degrading cell walls with a mixture of the appropriate polysaccharide-degrading enzymes: During and subsequent to digestion of the cell wall, the protoplast becomes very sensitive to osmosis, osmotic stress. This means cell wal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eyespot Apparatus
The eyespot apparatus (or '' stigma'') is a photoreceptive organelle found in the flagellate or (motile) cells of green algae and other unicellular photosynthetic organisms such as euglenids. It allows the cells to sense light direction and intensity and respond to it, prompting the organism to either swim towards the light (positive phototaxis), or away from it (negative phototaxis). A related response ("photoshock" or photophobic response) occurs when cells are briefly exposed to high light intensity, causing the cell to stop, briefly swim backwards, then change swimming direction. Eyespot-mediated light perception helps the cells in finding an environment with optimal light conditions for photosynthesis. Eyespots are the simplest and most common "eyes" found in nature, composed of photoreceptors and areas of bright orange-red red pigment granules. Signals relayed from the eyespot photoreceptors result in alteration of the beating pattern of the flagella, generating a photo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
