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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] |
Eukaryota
Eukaryotes () are organisms whose Cell (biology), cells have a cell nucleus, nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the Three-domain system, three domains of life. Bacteria and Archaea (both prokaryotes) make up the other two domains. The eukaryotes are usually now regarded as having emerged in the Archaea or as a sister of the Asgard (archaea), Asgard archaea. This implies that there are only Two-domain system, two domains of life, Bacteria and Archaea, with eukaryotes incorporated among archaea. Eukaryotes represent a small minority of the number of organisms, but, due to their generally much larger size, their collective global biomass (ecology), biomass is estimated to be about equal to that of prokaryotes. Eukaryotes emerged approximately 2.3–1.8 billion years ago, during the Proterozoic eon, likely as Flagellated cell, flagellated phagotrophs. The ... [...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] |
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] |
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] |
Mitosis
In cell biology, mitosis () is a part of the cell cycle in which replicated chromosomes are separated into two new nuclei. Cell division by mitosis gives rise to genetically identical cells in which the total number of chromosomes is maintained. Therefore, mitosis is also known as equational division. In general, mitosis is preceded by S phase of interphase (during which DNA replication occurs) and is often followed by telophase and cytokinesis; which divides the cytoplasm, organelles and cell membrane of one cell into two new cells containing roughly equal shares of these cellular components. The different stages of mitosis altogether define the mitotic (M) phase of an animal cell cycle—the division of the mother cell into two daughter cells genetically identical to each other. The process of mitosis is divided into stages corresponding to the completion of one set of activities and the start of the next. These stages are preprophase (specific to plant cells), prophase ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
