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Sphaeroplea Tenuis
''Sphaeroplea'' is a genus of green algae in the family Sphaeropleaceae. It was first circumscribed by the Swedish botanist Carl Adolph Agardh in 1824. Description ''Sphaeroplea'' consists of unbranched filaments of cells, one cell thick. Cells are usually 10–50 μm in diameter, but one variety can reach up to 170 μm in diameter. Cells are cylindrical, several times longer than wide, with a linear series of alternating vacuoles and cytoplasmic zones containing nuclei and chloroplasts. The chloroplasts are band-shaped, and contain several pyrenoids. Nuclei are typically in pairs. Reproduction ''Sphaeroplea'' reproduces asexually and sexually. In asexual reproduction, the filaments break apart, although one species has been observed to produce zoospores that are biflagellate (i.e. with two flagella). Sexual reproduction is typically oogamous, where vegetative cells become reproductive cells without changing their shape. Female gametes are large, spherical and green, and are bor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcareous
Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime (mineral), lime or being chalky. The term is used in a wide variety of Science, scientific disciplines. In zoology ''Calcareous'' is used as an adjectival term applied to anatomical structures which are made primarily of calcium carbonate, in animals such as gastropods, i.e., snails, specifically in relation to such structures as the operculum (gastropod), operculum, the clausilium, and the love dart. The term also applies to the calcium carbonate Test (biology), tests of, often, more-or-less microscopic Foraminifera. Not all tests are calcareous; diatoms and radiolaria have siliceous tests. The molluscs are calcareous organisms, as are the Calcarea, calcareous sponges (Calcarea), that have spicules which are made of calcium carbonate. Additionally, reef-building corals, or Scleractinia, are calcareous organisms that form their rigid skeletal structure th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphaeroplea Miocenica
''Sphaeroplea'' is a genus of green algae in the family Sphaeropleaceae. It was first circumscribed by the Swedish botanist Carl Adolph Agardh in 1824. Description ''Sphaeroplea'' consists of unbranched filaments of cells, one cell thick. Cells are usually 10–50 μm in diameter, but one variety can reach up to 170 μm in diameter. Cells are cylindrical, several times longer than wide, with a linear series of alternating vacuoles and cytoplasmic zones containing nuclei and chloroplasts. The chloroplasts are band-shaped, and contain several pyrenoids. Nuclei are typically in pairs. Reproduction ''Sphaeroplea'' reproduces asexually and sexually. In asexual reproduction, the filaments break apart, although one species has been observed to produce zoospores that are biflagellate (i.e. with two flagella). Sexual reproduction is typically oogamous, where vegetative cells become reproductive cells without changing their shape. Female gametes are large, spherical and green, and are bor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Though the fossil record is incomplete, numerous studies have demonstrated that there is enough information available to give a good understanding of the pattern of diversification of life on Earth. In addition, the record can predict and fill gaps such as the discovery of '' Tiktaalik'' in the arctic of Canada. Paleontology includes the study of fossils: their age, method of formation, and evolutionary significance. Specimens are sometimes considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years to 4.1 billion years old. Early edition, published online before prin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphaeroplea Willmanii
''Sphaeroplea'' is a genus of green algae in the family Sphaeropleaceae. It was first circumscribed by the Swedish botanist Carl Adolph Agardh in 1824. Description ''Sphaeroplea'' consists of unbranched filaments of cells, one cell thick. Cells are usually 10–50 μm in diameter, but one variety can reach up to 170 μm in diameter. Cells are cylindrical, several times longer than wide, with a linear series of alternating vacuoles and cytoplasmic zones containing nuclei and chloroplasts. The chloroplasts are band-shaped, and contain several pyrenoids. Nuclei are typically in pairs. Reproduction ''Sphaeroplea'' reproduces asexually and sexually. In asexual reproduction, the filaments break apart, although one species has been observed to produce zoospores that are biflagellate (i.e. with two flagella). Sexual reproduction is typically oogamous, where vegetative cells become reproductive cells without changing their shape. Female gametes are large, spherical and green, and are bor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
