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Eudorina Compacta
''Eudorina'' is a genus of green algae in the family Volvocaceae, containing about seven species. It has a cosmopolitan distribution in freshwater habitats. Description ''Eudorina'' colonies typically consist of 16, 32 or 64 cells, each of which is similar to ''Chlamydomonas reinhardtii''. These cells are bedded within an extracellular matrix composed of glycoproteins. Colonies are spherical and motile, with motility derived from the flagellated individual cells. Cells are ovoid or spherical, each with two equal flagella. (In one species ''Eudorina compacta'', the cells essentially touch each other, and are strikingly angular due to mutual compression.) There is a single cup-shaped chloroplast with one (basal) or multiple pyrenoids) and a eyespot apparatus, stigma. Multiple contractile vacuoles are scattered throughout the cytoplasm. ''Eudorina'' is facultatively sexual, meaning colonies can reproduce either sexually or asexually. During development, each ''Chlamydomonas''-lik ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volvox Aureus
''Volvox aureus'' is a species of colonial green algae in the family Volvocaceae. It is a freshwater alga with a cosmopolitan distribution, and is probably the most commonly reported species of the genus ''Volvox''. It is common in lowland lakes, rivers, ponds, ditches, and puddles, and is most abundant in late summer. Description ''Volvox aureus'' consists of motile, spherical colonies of cells, typically around 400–600 μm in diameter. Colonies contain approximately 500–3200 cells, arranged in one layer around the margin of a hollow sphere or ellipsoid. Cells are connected to each other by thin cytoplasmic strands, approximately the same thickness as the flagella. Cells are surrounded by a confluent gelatinous sheath of cells; the center of the colony has a homogeneous mass from which gelatinous strands radiate outward and connect with the inner layer of the colonial matrix. Within the colony, there are four to 12 gonidia irregularly distributed in the posterior half. Goni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleodorina Indica
''Pleodorina'' is a genus of colonial green algae in the family Volvocaceae. It occurs in freshwater habitats and has a cosmopolitan distribution. Description ''Pleodorina'' consists of motile colonies of 32 to 128 cells, which are arranged in the periphery of a gelatinous matrix, forming a hollow sphere. Cells are differentiated into those that are purely vegetative in character (somatic cells) and those capable of dividing to form daughter colonies (reproductive cells). Somatic cells are smaller than reproductive cells; somatic cells are located in the anterior part of the colony, while reproductive cells occupy the rest of the colony. In one species '' Pleodorina sphaerica'', somatic cells are also randomly distributed amongst reproductive cells. In some species, individual cells are surrounded by a gelatinous sheath. All cells are biflagellate (with two equal flagella), and have a cup-shaped chloroplast, an stigma, many contractile vacuoles, and one to many pyrenoids. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleodorina Starrii
''Pleodorina starrii'' is a species of algae that resides in freshwater in Japan. The name ''starri'' is in honor of phycologist Richard C. Starr. Since 2006 it has provided molecular genetic evidence for an evolutionary link between sexes and mating types. It was later confirmed to be the first reportedly trioecious haploid species. Description ''Pleodorina starrii'' is a colonial organism. The colonies are spherical or ellipsoidal and consist of 32 or 64 biflagellate cells embedded in the periphery of a gelatinous matrix, thus forming a hollow sphere. Cells are differentiated into somatic and reproductive cells; in 32-celled colonies, 8–12 of the cells are somatic while in 64-celled colonies, 18–20 of the cells are somatic. Somatic cells are nearly spherical, up to 13 μm in diameter, having a cup-shaped chloroplast with a single pyrenoid. Two contractile vacuoles are present near the base of the flagella, as well as several others near the cell surface. Reproductive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eudorina Peripheralis
''Eudorina'' is a genus of green algae in the family Volvocaceae, containing about seven species. It has a cosmopolitan distribution in freshwater habitats. Description ''Eudorina'' colonies typically consist of 16, 32 or 64 cells, each of which is similar to ''Chlamydomonas reinhardtii''. These cells are bedded within an extracellular matrix composed of glycoproteins. Colonies are spherical and motile, with motility derived from the flagellated individual cells. Cells are ovoid or spherical, each with two equal flagella. (In one species ''Eudorina compacta'', the cells essentially touch each other, and are strikingly angular due to mutual compression.) There is a single cup-shaped chloroplast with one (basal) or multiple pyrenoids) and a stigma. Multiple contractile vacuoles are scattered throughout the cytoplasm. ''Eudorina'' is facultatively sexual, meaning colonies can reproduce either sexually or asexually. During development, each ''Chlamydomonas''-like cell undergoes s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleodorina Thompsonii
''Pleodorina'' is a genus of colonial green algae in the family Volvocaceae. It occurs in freshwater habitats and has a cosmopolitan distribution. Description ''Pleodorina'' consists of motile colonies of 32 to 128 cells, which are arranged in the periphery of a gelatinous matrix, forming a hollow sphere. Cells are differentiated into those that are purely vegetative in character (somatic cells) and those capable of dividing to form daughter colonies (reproductive cells). Somatic cells are smaller than reproductive cells; somatic cells are located in the anterior part of the colony, while reproductive cells occupy the rest of the colony. In one species '' Pleodorina sphaerica'', somatic cells are also randomly distributed amongst reproductive cells. In some species, individual cells are surrounded by a gelatinous sheath. All cells are biflagellate (with two equal flagella), and have a cup-shaped chloroplast, an stigma, many contractile vacuoles, and one to many pyrenoids. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somatic (biology)
In cellular biology, the term somatic is derived from the French somatique which comes from Ancient Greek σωματικός (sōmatikós, “bodily”), and σῶμα (sôma, “body”.) is often used to refer to the cells of the body, in contrast to the reproductive ( germline) cells, which usually give rise to the egg or sperm (or other gametes in other organisms). These somatic cells are diploid, containing two copies of each chromosome, whereas germ cells are haploid, as they only contain one copy of each chromosome (in preparation for fertilisation). Although under normal circumstances all somatic cells in an organism contain identical DNA, they develop a variety of tissue-specific characteristics. This process is called differentiation, through epigenetic and regulatory alterations. The grouping of similar cells and tissues creates the foundation for organs. Somatic mutations are changes to the genetics of a multicellular organism that are not passed on to its offspr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volvox
''Volvox'' is a polyphyletic genus of chlorophyte green algae in the family Volvocaceae. ''Volvox'' species form spherical colonies of up to 50,000 cells, and for this reason they are sometimes called globe algae. First reported by Antonie van Leeuwenhoek in 1700, it is distinctive and easily identified in the microscope. It occurs in variety of freshwater habitats, and has a widespread, cosmopolitan distribution. ''Volvox'' diverged from unicellular ancestors approximately . Colonies of ''Volvox'' are differentiated into somatic and reproductive cells, and are capable of both sexual and asexual reproduction. Additionally, its close relatives are diverse in body plan and reproductive strategy, ranging from unicellular organisms such as '' Chlamydomonas'' to simple colonial organisms such as '' Pandorina'' and '' Eudorina''. Because of this, ''Volvox'' and its relatives are used as model organisms in the classroom and laboratory to study biological processes such as cellular move ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleodorina
''Pleodorina'' is a genus of colonial green algae in the family Volvocaceae. It occurs in freshwater habitats and has a cosmopolitan distribution. Description ''Pleodorina'' consists of motile colonies of 32 to 128 cells, which are arranged in the periphery of a gelatinous matrix, forming a hollow sphere. Cells are differentiated into those that are purely vegetative in character (somatic cells) and those capable of dividing to form daughter colonies (reproductive cells). Somatic cells are smaller than reproductive cells; somatic cells are located in the anterior part of the colony, while reproductive cells occupy the rest of the colony. In one species '' Pleodorina sphaerica'', somatic cells are also randomly distributed amongst reproductive cells. In some species, individual cells are surrounded by a gelatinous sheath. All cells are biflagellate (with two equal flagella), and have a cup-shaped chloroplast, an stigma, many contractile vacuoles, and one to many pyrenoids. The ... [...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] |
Molecular Phylogenetic
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to determine the processes by which diversity among species has been achieved. The result of a molecular phylogenetic analysis is expressed in a phylogenetic tree. Molecular phylogenetics is one aspect of molecular systematics, a broader term that also includes the use of molecular data in taxonomy and biogeography. Molecular phylogenetics and molecular evolution correlate. Molecular evolution is the process of selective changes (mutations) at a molecular level (genes, proteins, etc.) throughout various branches in the tree of life (evolution). Molecular phylogenetics makes inferences of the evolutionary relationships that arise due to molecular evolution and results in the construction of a phylogenetic tree. History The theoretical fra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
