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Gonimoblast
A gonimoblast is a type of cell produced by red algae upon the fertilization of a zygotic nucleus, and involved in the formation of carpospores. The cells subsequently divide and ultimately serve as storage or generative cells. Storage cells contain starch and are multinucleate; whereas generative cells are situated further from the auxiliary cell, are uninucleate, and form the terminal lobes in the ensuing carpospores. Gonimoblasts are connected by septal pore In algal anatomy, a pit connection is a hole in the septum between two algal cells, and is found only in the red algae − specifically, all orders except the Porphyridiales and haploid Bangiales. They are often stoppered with proteinaceous "pit p ...s, usually blocked by septal plugs. References Algal anatomy {{Alga-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell (biology)
The cell is the basic structural and functional unit of life forms. Every cell consists of a cytoplasm enclosed within a membrane, and contains many biomolecules such as proteins, DNA and RNA, as well as many small molecules of nutrients and metabolites.Cell Movements and the Shaping of the Vertebrate Body in Chapter 21 of Molecular Biology of the Cell '' fourth edition, edited by Bruce Alberts (2002) published by Garland Science. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos. It is also common to describe small molecules such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Algae
Red algae, or Rhodophyta (, ; ), are one of the oldest groups of eukaryotic algae. The Rhodophyta also comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority of species (6,793) are found in the Florideophyceae (class), and mostly consist of multicellular, marine algae, including many notable seaweeds. Red algae are abundant in marine habitats but relatively rare in freshwaters. Approximately 5% of red algae species occur in freshwater environments, with greater concentrations found in warmer areas. Except for two coastal cave dwelling species in the asexual class Cyanidiophyceae, there are no terrestrial species, which may be due to an evolutionary bottleneck in which the last common ancestor lost about 25% of its core genes and much of its evolutionary plasticity. The red algae form a distinct group characterized by having eukaryotic cells without flagella and centrioles, chloroplasts that l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zygote
A zygote (, ) is a eukaryotic cell formed by a fertilization event between two gametes. The zygote's genome is a combination of the DNA in each gamete, and contains all of the genetic information of a new individual organism. In multicellular organisms, the zygote is the earliest developmental stage. In humans and most other anisogamous organisms, a zygote is formed when an egg cell and sperm cell come together to create a new unique organism. In single-celled organisms, the zygote can divide asexually by mitosis to produce identical offspring. German zoologists Oscar and Richard Hertwig made some of the first discoveries on animal zygote formation in the late 19th century. Humans In human fertilization, a released ovum (a haploid secondary oocyte with replicate chromosome copies) and a haploid sperm cell (male gamete) combine to form a single diploid cell called the zygote. Once the single sperm fuses with the oocyte, the latter completes the division of the second ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Nucleus
The cell nucleus (pl. nuclei; from Latin or , meaning ''kernel'' or ''seed'') is a membrane-bound organelle found in eukaryotic cells. Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have no nuclei, and a few others including osteoclasts have many. The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and isolates its contents from the cellular cytoplasm; and the nuclear matrix, a network within the nucleus that adds mechanical support. The cell nucleus contains nearly all of the cell's genome. Nuclear DNA is often organized into multiple chromosomes – long stands of DNA dotted with various proteins, such as histones, that protect and organize the DNA. The genes within these chromosomes are structured in such a way to promote cell function. The nucleus maintains the integrity of genes and controls the activities of the cell by regulating gene expres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carpospore
A carpospore is a diploid spore produced by red algae. After fertilization, the alga's carpogonium subdivides into carpospores, and generally the largest type of spore (larger than bispores, which are larger again than tetraspores Tetraspores are red algae spores produced by the tetrasporophytic ( diploid) phase in the life history of algae in the Rhodophyta as a result of meiosis.Jones, W.E. Revised and reprinted 1964. A Key to the genera of the British seaweeds.''Field ...). The wall of the carposporangium then breaks down, releasing the spores into the environment. References Red algae {{rhodophyta-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Division
Cell division is the process by which a parent cell (biology), cell divides into two daughter cells. Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome(s) before dividing. In eukaryotes, there are two distinct types of cell division: a vegetative division (mitosis), producing daughter cells genetically identical to the parent cell, and a cell division that produces Haploidisation, haploid gametes for sexual reproduction (meiosis), reducing the number of chromosomes from two of each type in the diploid parent cell to one of each type in the daughter cells. In cell biology, mitosis (Help:IPA/English, /maɪˈtoʊsɪs/) is a part of the cell cycle, in which, replicated chromosomes are separated into two new Cell nucleus, nuclei. Cell division gives rise to genetically identical cells in which the total number of chromosomes is maintained. In general, mitosis (division of the nucleus) is preceded by the S stage of interph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Starch
Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diets, and is contained in large amounts in staple foods such as wheat, potatoes, maize (corn), rice, and cassava (manioc). Pure starch is a white, tasteless and odorless powder that is insoluble in cold water or alcohol. It consists of two types of molecules: the linear and helical amylose and the branched amylopectin. Depending on the plant, starch generally contains 20 to 25% amylose and 75 to 80% amylopectin by weight. Glycogen, the energy reserve of animals, is a more highly branched version of amylopectin. In industry, starch is often converted into sugars, for example by malting. These sugars may be fermented to produce ethanol in the manufacture of beer, whisky and biofuel. In addition, sugars produced from processed starch are used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multinucleate
Multinucleate cells (also known as multinucleated or polynuclear cells) are eukaryotic cells that have more than one nucleus per cell, i.e., multiple nuclei share one common cytoplasm. Mitosis in multinucleate cells can occur either in a coordinated, synchronous manner where all nuclei divide simultaneously or asynchronously where individual nuclei divide independently in time and space. Certain organisms may have a multinuclear stage of their life cycle. For example, slime molds have a vegetative, multinucleate life stage called a plasmodium. Although not normally viewed as a case of multinucleation, plant cells share a common cytoplasm by plasmodesmata, and most cells in animal tissues are in communication with their neighbors via gap junctions. Multinucleate cells, depending on the mechanism by which they are formed, can be divided into "syncytia" (formed by cell fusion) or "coenocytes" (formed by nuclear division not being followed by cytokinesis). A number of dinoflagellat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auxiliary Cell
The auxiliary cell is a spore-like structure that form within the fungal family Gigasporaceae (order Gigasporales). Auxiliary cells have thin cell walls, (spiny), papillate, knobby or sometimes smooth surfaces, and are formed from hyphae after spore germination before the formation of mycorrhizae, and then on the extraradical hyphae in the soil. They may not be 'cells' in the biological sense of the word, as they are structures found with coenocytic hyphae belonging to members of the phylum (division) Glomeromycota. Mostly they are known from members of the Gigasporaceae. Currently this family contains '' Gigaspora'', '' Scutellospora'' and '' Racocetra'', but there are other generic names that have not been widely accepted (''Dentiscutata'', ''Cetraspora'', ''Fuscutata'' and ''Quatunica'') — all of these form auxiliary cells. Members of the genus '' Pacispora'' (another genus in the Diversisporales The ''Diversisporales'' are an order of generally hypogeous (underground ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uninucleate
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Septal Pore
In algal anatomy, a pit connection is a hole in the septum between two algal cells, and is found only in the red algae − specifically, all orders except the Porphyridiales and haploid Bangiales. They are often stoppered with proteinaceous "pit plugs". By contrast, many fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ... (only ascomycetes and basidiomycetes, as most other groups lack septa) contain septal pores − an unrelated phenomenon. Characteristics A sieve-like membrane may cover the pit in living algae, but in the majority of algae a plug forms, they likely limit the transfer of metabolites between neighbouring cells. Formation Primary pit connections are formed between cells in the same filament, derived from the same parent cell by its division. Such connections ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biology Of The Cell
''Biology of the Cell'' is a peer-reviewed scientific journal in the field of cell biology, cell physiology, and molecular biology of animal and plant cells, microorganisms and protists. Topics covered include development, neurobiology, and immunology, as well as theoretical or biophysical modelling. The journal is currently published monthly by Wiley-Blackwell on behalf of the Société Française des Microscopies and the Société de Biologie Cellulaire de France.Osborne HB. (2005) What's new for Biology of the Cell in 2005? (Editorial) ''Biol Cell'' 97: 1–2 (accessed 23 October 2007) History The journal first appeared in 1962 and was originally titled ''Journal de Microscopie'' (1962–1974). In 1975 the journal was r ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
