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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 ... [...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 ... [...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 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 ... [...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 ''wikt:cyrtos, 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. ... [...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 cylinde ... [...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 (biology), 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 domain (biology), domains of Archaea and Bacteria reproduce with binary fission. This form of asexual reproduction and cell division is also used by some organelles within eukaryote, eukaryotic organisms (e.g., mitochondrion, mitochondria). Binary fission results in the reproduction of a living prokaryote, prokaryotic cell (biology), cell (or organelle) by dividing the cell into two parts, each with the potential to grow to the size of the original. Fission of pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haploid
Ploidy () is the number of complete sets of chromosomes in a cell (biology), cell, and hence the number of possible alleles for Autosome, autosomal and Pseudoautosomal region, pseudoautosomal genes. Here ''sets of chromosomes'' refers to the number of maternal and paternal chromosome copies, respectively, in each homologous chromosome pair—the form in which chromosomes naturally exist. Somatic cells, Tissue (biology), tissues, and Individual#Biology, 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 polyploidy, polyploid is often used to describe cells with three or more sets of chromosomes. Virtually all sexual reproduction, sexually reproducing organisms are made up of somatic cells that are diploid or greater, but ploidy level may vary wid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meiosis
Meiosis () is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, the sperm or egg cells. It involves two rounds of division that ultimately result in four cells, each 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 a female will fuse to create a zygote, a cell with two copies of each chromosome. 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 chromosomes as the original parent cell. ... [...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), and is found in most unicellular eukaryotes. Because both gametes look alike, they generally cannot be classified as male or female. Instead, organisms that reproduce through isogamy are said to have different mating types, most commonly noted as "+" and "−" strains. Etymology The etymology of isogamy derives from the Greek adjective ''isos'' (meaning equal) and the Greek verb ''gameo'' (meaning to have sex/to reproduce), eventually meaning "equal reproduction" which refers to a hypothetical initial model of equal contribution of resources by both gametes to a zygote in contrast to a later evolutional stage of anisogamy. The term isogamy was first used in the year 1891. Characteristics of isogamous species Isogamous species often have two mating types ( heterothallism), but sometimes can occur between two haploid individuals that are mitotic d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
