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Nassula
''Nassula'' is a genus of unicellular ciliates, belonging to the class Nassophorea. Like other members of the class, ''Nassula'' possesses a basket-like feeding apparatus (''nasse'', or ''cyrtos'') made up of cytopharyngeal rods (''nematodesmata''), which are themselves composed of closely packed microtubules. ''Nassula'' use this structure to ingest filamentous cyanobacteria, drawing individual strands of blue-green algae through the cytopharynx and into the body of the cell, where they are digested. As the algae are broken down, they can take on a variety of bright colours, which give ''Nassula'' a distinctive, variegated appearance under the microscope. Description The body is ovoid to elongate, and uniformly ciliated, with a single macronucleus and a partial hypostomial frange (''synhymenium'') running from the left side of the cell to the oral aperture. When food is scarce, members of the genus have the ability to become dormant by forming a microbial cyst. Excystment c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nassula Aureola
''Nassula'' is a genus of unicellular ciliates, belonging to the class Nassophorea. Like other members of the class, ''Nassula'' possesses a basket-like feeding apparatus (''nasse'', or ''cyrtos'') made up of cytopharyngeal rods (''nematodesmata''), which are themselves composed of closely packed microtubules. ''Nassula'' use this structure to ingest filamentous cyanobacteria, drawing individual strands of blue-green algae through the cytopharynx and into the body of the cell, where they are digested. As the algae are broken down, they can take on a variety of bright colours, which give ''Nassula'' a distinctive, variegated appearance under the microscope. Description The body is ovoid to elongate, and uniformly ciliated, with a single macronucleus and a partial hypostomial frange (''synhymenium'') running from the left side of the cell to the oral aperture. When food is scarce, members of the genus have the ability to become dormant by forming a microbial cyst. Excystment c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nassula Argentula
''Nassula'' is a genus of unicellular ciliates, belonging to the class Nassophorea. Like other members of the class, ''Nassula'' possesses a basket-like feeding apparatus (''nasse'', or ''cyrtos'') made up of cytopharyngeal rods (''nematodesmata''), which are themselves composed of closely packed microtubules. ''Nassula'' use this structure to ingest filamentous cyanobacteria, drawing individual strands of blue-green algae through the cytopharynx and into the body of the cell, where they are digested. As the algae are broken down, they can take on a variety of bright colours, which give ''Nassula'' a distinctive, variegated appearance under the microscope. Description The body is ovoid to elongate, and uniformly ciliated, with a single macronucleus and a partial hypostomial frange (''synhymenium'') running from the left side of the cell to the oral aperture. When food is scarce, members of the genus have the ability to become dormant by forming a microbial cyst. Excystment c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nassula Ambigua
''Nassula'' is a genus of unicellular ciliates, belonging to the class Nassophorea. Like other members of the class, ''Nassula'' possesses a basket-like feeding apparatus (''nasse'', or ''cyrtos'') made up of cytopharyngeal rods (''nematodesmata''), which are themselves composed of closely packed microtubules. ''Nassula'' use this structure to ingest filamentous cyanobacteria, drawing individual strands of blue-green algae through the cytopharynx and into the body of the cell, where they are digested. As the algae are broken down, they can take on a variety of bright colours, which give ''Nassula'' a distinctive, variegated appearance under the microscope. Description The body is ovoid to elongate, and uniformly ciliated, with a single macronucleus and a partial hypostomial frange (''synhymenium'') running from the left side of the cell to the oral aperture. When food is scarce, members of the genus have the ability to become dormant by forming a microbial cyst. Excystment c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nassula A Colorful Ciliate Detail Of Cytopharyngea
''Nassula'' is a genus of unicellular ciliates, belonging to the class Nassophorea. Like other members of the class, ''Nassula'' possesses a basket-like feeding apparatus (''nasse'', or ''cyrtos'') made up of cytopharyngeal rods (''nematodesmata''), which are themselves composed of closely packed microtubules. ''Nassula'' use this structure to ingest filamentous cyanobacteria, drawing individual strands of blue-green algae through the cytopharynx and into the body of the cell, where they are digested. As the algae are broken down, they can take on a variety of bright colours, which give ''Nassula'' a distinctive, variegated appearance under the microscope. Description The body is ovoid to elongate, and uniformly ciliated, with a single macronucleus and a partial hypostomial frange (''synhymenium'') running from the left side of the cell to the oral aperture. When food is scarce, members of the genus have the ability to become dormant by forming a microbial cyst. Excystment c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nassula Consuming Strands Of Cyanobacteria
''Nassula'' is a genus of unicellular ciliates, belonging to the class Nassophorea. Like other members of the class, ''Nassula'' possesses a basket-like feeding apparatus (''nasse'', or ''cyrtos'') made up of cytopharyngeal rods (''nematodesmata''), which are themselves composed of closely packed microtubules. ''Nassula'' use this structure to ingest filamentous cyanobacteria, drawing individual strands of blue-green algae through the cytopharynx and into the body of the cell, where they are digested. As the algae are broken down, they can take on a variety of bright colours, which give ''Nassula'' a distinctive, variegated appearance under the microscope. Description The body is ovoid to elongate, and uniformly ciliated, with a single macronucleus and a partial hypostomial frange (''synhymenium'') running from the left side of the cell to the oral aperture. When food is scarce, members of the genus have the ability to become dormant by forming a microbial cyst. Excystment c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nassula Ornata Details
''Nassula'' is a genus of unicellular ciliates, belonging to the class Nassophorea. Like other members of the class, ''Nassula'' possesses a basket-like feeding apparatus (''nasse'', or ''cyrtos'') made up of cytopharyngeal rods (''nematodesmata''), which are themselves composed of closely packed microtubules. ''Nassula'' use this structure to ingest filamentous cyanobacteria, drawing individual strands of blue-green algae through the cytopharynx and into the body of the cell, where they are digested. As the algae are broken down, they can take on a variety of bright colours, which give ''Nassula'' a distinctive, variegated appearance under the microscope. Description The body is ovoid to elongate, and uniformly ciliated, with a single macronucleus and a partial hypostomial frange (''synhymenium'') running from the left side of the cell to the oral aperture. When food is scarce, members of the genus have the ability to become dormant by forming a microbial cyst. Excystment c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nassula Ciliate Cell Division
''Nassula'' is a genus of unicellular ciliates, belonging to the class Nassophorea. Like other members of the class, ''Nassula'' possesses a basket-like feeding apparatus (''nasse'', or ''cyrtos'') made up of cytopharyngeal rods (''nematodesmata''), which are themselves composed of closely packed microtubules. ''Nassula'' use this structure to ingest filamentous cyanobacteria, drawing individual strands of blue-green algae through the cytopharynx and into the body of the cell, where they are digested. As the algae are broken down, they can take on a variety of bright colours, which give ''Nassula'' a distinctive, variegated appearance under the microscope. Description The body is ovoid to elongate, and uniformly ciliated, with a single macronucleus and a partial hypostomial frange (''synhymenium'') running from the left side of the cell to the oral aperture. When food is scarce, members of the genus have the ability to become dormant by forming a microbial cyst. Excystment c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nassophorea
The Nassophorea are a class of ciliates. Members are free-living, usually in freshwater but also in marine and soil environments. The mouth is anterior ventral and leads to a curved cytopharynx supported by a prominent palisade of rods or ''nematodesmata'', forming a structure called a ''cyrtos'' or ''nasse'', typical of this and a few other classes. When present, extrusomes take the form of fibrous trichocysts. Cilia are usually monokinetids, but vary from order to order. The Synhymeniida and Nassulida have mostly uniform cilia arising from monokinetids. Among the former, and a few members of the latter, there is a series of small polykinetids running from below the mouth to the left side of the body and sometimes almost circling the cell, called a ''frange'' or ''synhymenium''. Other forms only have three oral membranelles, sometimes extending out of the oral cavity, with or without a paroral membrane. These are usually medium in size, sometimes larger, and cylinder sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fission (biology)
Fission, in biology, is the division of a single entity into two or more parts and the regeneration of those parts to separate entities resembling the original. The object experiencing fission is usually a cell, but the term may also refer to how organisms, bodies, populations, or species split into discrete parts. The fission may be ''binary fission'', in which a single organism produces two parts, or ''multiple fission'', in which a single entity produces multiple parts. Binary fission Organisms in the domains of Archaea and Bacteria reproduce with binary fission. This form of asexual reproduction and cell division is also used by some organelles within eukaryotic organisms (e.g., mitochondria). Binary fission results in the reproduction of a living prokaryotic cell (or organelle) by dividing the cell into two parts, each with the potential to grow to the size of the original. Fission of prokaryotes The single DNA molecule first replicates, then attaches each copy to a differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haploid
Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively, in each homologous chromosome pair, which chromosomes naturally exist as. Somatic cells, tissues, and individual organisms can be described according to the number of sets of chromosomes present (the "ploidy level"): monoploid (1 set), diploid (2 sets), triploid (3 sets), tetraploid (4 sets), pentaploid (5 sets), hexaploid (6 sets), heptaploid or septaploid (7 sets), etc. The generic term polyploid is often used to describe cells with three or more chromosome sets. Virtually all sexually reproducing organisms are made up of somatic cells that are diploid or greater, but ploidy level may vary widely between different organisms, between different tissues within the same organism, and at different stages in an organism's life cycle. Half ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meiosis
Meiosis (; , since it is a reductional division) is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, such as sperm or egg cells. It involves two rounds of division that ultimately result in four cells with only one copy of each chromosome ( haploid). Additionally, prior to the division, genetic material from the paternal and maternal copies of each chromosome is crossed over, creating new combinations of code on each chromosome. Later on, during fertilisation, the haploid cells produced by meiosis from a male and female will fuse to create a cell with two copies of each chromosome again, the zygote. Errors in meiosis resulting in aneuploidy (an abnormal number of chromosomes) are the leading known cause of miscarriage and the most frequent genetic cause of developmental disabilities. In meiosis, DNA replication is followed by two rounds of cell division to produce four daughter cells, each with half the number of chr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Conjugation
Isogamy is a form of sexual reproduction that involves gametes of the same morphology (indistinguishable in shape and size), found in most unicellular eukaryotes. Because both gametes look alike, they generally cannot be classified as male or female. Instead, organisms undergoing isogamy are said to have different mating types, most commonly noted as "+" and "−" strains. Etymology The literal meaning of isogamy is "equal marriage" which refers to equal contribution of resources by both gametes to a zygote. The term isogamous was first used in the year 1887. Characteristics of isogamous species Isogamous species often have two mating types. Some isogamous species have more than two mating types, but the number is usually lower than ten. In some extremely rare cases a species can have thousands of mating types. In all cases, fertilization occurs when gametes of two different mating types fuse to form a zygote. Evolution It is generally accepted that isogamy is an an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
