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Volvox
''Volvox'' is a polyphyletic genus of chlorophyte green algae in the family Volvocaceae. It forms spherical colonies of up to 50,000 cells. They live in a variety of freshwater habitats, and were first reported by Antonie van Leeuwenhoek in 1700. ''Volvox'' diverged from unicellular ancestors approximately . Description ''Volvox'' is a polyphyletic genus in the volvocine green algae clade. Each mature ''Volvox'' colony is composed of up to thousands of cells from two differentiated cell types: numerous flagellate somatic cells and a smaller number of germ cells lacking in soma that are embedded in the surface of a hollow sphere or coenobium containing an extracellular matrix made of glycoproteins. Adult somatic cells comprise a single layer with the flagella facing outward. The cells swim in a coordinated fashion, with distinct anterior and posterior poles. The cells have anterior eyespots that enable the colony to swim toward light. The cells of colonies in the more ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volvox Aureus
''Volvox'' is a polyphyletic genus of chlorophyte green algae in the family Volvocaceae. It forms spherical colonies of up to 50,000 cells. They live in a variety of freshwater habitats, and were first reported by Antonie van Leeuwenhoek in 1700. ''Volvox'' diverged from unicellular ancestors approximately . Description ''Volvox'' is a polyphyletic genus in the volvocine green algae clade. Each mature ''Volvox'' colony is composed of up to thousands of cells from two differentiated cell types: numerous flagellate somatic cells and a smaller number of germ cells lacking in soma that are embedded in the surface of a hollow sphere or coenobium containing an extracellular matrix made of glycoproteins. Adult somatic cells comprise a single layer with the flagella facing outward. The cells swim in a coordinated fashion, with distinct anterior and posterior poles. The cells have anterior eyespots that enable the colony to swim toward light. The cells of colonies in the more basal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volvox
''Volvox'' is a polyphyletic genus of chlorophyte green algae in the family Volvocaceae. It forms spherical colonies of up to 50,000 cells. They live in a variety of freshwater habitats, and were first reported by Antonie van Leeuwenhoek in 1700. ''Volvox'' diverged from unicellular ancestors approximately . Description ''Volvox'' is a polyphyletic genus in the volvocine green algae clade. Each mature ''Volvox'' colony is composed of up to thousands of cells from two differentiated cell types: numerous flagellate somatic cells and a smaller number of germ cells lacking in soma that are embedded in the surface of a hollow sphere or coenobium containing an extracellular matrix made of glycoproteins. Adult somatic cells comprise a single layer with the flagella facing outward. The cells swim in a coordinated fashion, with distinct anterior and posterior poles. The cells have anterior eyespots that enable the colony to swim toward light. The cells of colonies in the more ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volvox Carteri
''Volvox carteri'' is a species of colonial green algae in the order Volvocales. The ''V. carteri'' life cycle includes a sexual phase and an asexual phase. ''V. carteri'' forms small spherical colonies, or coenobia, of 2000–6000 ''Chlamydomonas ''Chlamydomonas'' is a genus of green algae consisting of about 150 speciesSmith, G.M. 1955 ''Cryptogamic Botany Volume 1. Algae and Fungi'' McGraw-Hill Book Company Inc of unicellular flagellates, found in stagnant water and on damp soil, ...-''type somatic cells and 12–16 large, potentially immortal reproductive cells called gonidia. While vegetative, male and female colonies are indistinguishable; however, in the sexual phase, females produce 35-45 eggs and males produce up to 50 sperm packets with 64 or 128 sperm each. The genome of this species of algae was sequenced in 2010. ''Volvox carteri'' is a significant model organism for research into the evolution of multicellularity and organismal complexity, largely due to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volvox Globator
''Volvox globator'' is a species of green algae of the genus ''Volvox''. It was originally described by Carl Linnaeus in his 1758 work ''Systema Naturae''. In 1856 its sexuality was described by Ferdinand Cohn Ferdinand Julius Cohn (24 January 1828 – 25 June 1898) was a German biologist. He is one of the founders of modern bacteriology and microbiology. Ferdinand J. Cohn was born in the Jewish quarter of Breslau in the Prussian Province of Siles ... and is the same as '' Sphaeroplea'' ''annulina''.http://www.pnf.org/compendium/Ferdinand_Julius_Cohn.pdf It is colonial flagellate found in freshwaters. The colony consists of thousands of zooids (somatic cells) arranged in a single peripheral layer. each zooids shows two flagella, two or more contractile vacuoles, cup like chloroplast, a single nucleus, a red stigma but no gullet. Nutrition is holophytic. Size of colony increases by binary fission. In the colony the zooids called parthenogonidia repeatedly divide to form daug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volvocaceae
The Volvocaceae are a family of unicellular or colonial biflagellates, including the typical genus ''Volvox''. The family was named by Ehrenberg in 1834,From p. 281: ''"VOLVOCINA Nova Familia."'' (Volvocina New Family.) ote: According to p. 145, Ehrenberg's paper was first presented in 1832, revised somewhat, and published in 1834./ref> and is known in older classifications as the Volvocidae. All species are colonial and inhabit freshwater environments. Description The simplest of the Volvocaeans are ordered assemblies of cells, each similar to the related unicellular protist ''Chlamydomonas'' and embedded in a gelatinous matrix. In the genus ''Gonium'', for example, each individual organism is a flat plate consisting of 4 to 16 separate cells, each with two flagella. Similarly, the genera '' Eudorina'' and ''Pandorina'' form hollow spheres, the former consisting of 16 cells, the latter of 32 to 64 cells. In these genera each cell can reproduce a new organism by mitosis.Sco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green Algae
The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ( Embryophytes) have emerged deep in the Charophyte alga as sister of the Zygnematophyceae. Since the realization that the Embryophytes emerged within the green algae, some authors are starting to properly include them. The completed clade that includes both green algae and embryophytes is monophyletic and is referred to as the clade Viridiplantae and as the kingdom Plantae. The green algae include unicellular and colonial flagellates, most with two flagella per cell, as well as various colonial, coccoid and filamentous forms, and macroscopic, multicellular seaweeds. There are about 22,000 species of green algae. Many species live most of their lives as single cells, while other species form coenobia (colonies), long filaments, or highly differentiated macroscopic seaweeds. A few oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somatic Cell
A somatic cell (from Ancient Greek σῶμα ''sôma'', meaning "body"), or vegetal cell, is any biological cell forming the body of a multicellular organism other than a gamete, germ cell, gametocyte or undifferentiated stem cell. Such cells compose the body of an organism and divide through the process of binary fission and mitotic division. In contrast, gametes are cells that fuse during sexual reproduction, germ cells are cells that give rise to gametes, and stem cells are cells that can divide through mitosis and differentiate into diverse specialized cell types. For example, in mammals, somatic cells make up all the internal organs, skin, bones, blood and connective tissue, while mammalian germ cells give rise to spermatozoa and ova which fuse during fertilization to produce a cell called a zygote, which divides and differentiates into the cells of an embryo. There are approximately 220 types of somatic cell in the human body. Theoretically, these cells are not germ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colony (biology)
In biology, a colony is composed of two or more conspecific individuals living in close association with, or connected to, one another. This association is usually for mutual benefit such as stronger defense or the ability to attack bigger prey. Colonies can form in various shapes and ways depending on the organism involved. For instance, the bacterial colony is a cluster of identical cells (clones). These colonies often form and grow on the surface of (or within) a solid medium, usually derived from a single parent cell. Colonies, in the context of development, may be composed of two or more unitary (or solitary) organisms or be modular organisms. Unitary organisms have determinate development (set life stages) from zygote to adult form and individuals or groups of individuals (colonies) are visually distinct. Modular organisms have indeterminate growth forms (life stages not set) through repeated iteration of genetically identical modules (or individuals), and it can be diffi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
