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Plastids Types
The plastid (Greek: πλαστός; plastós: formed, molded – plural plastids) is a membrane-bound organelle found in the cells of plants, algae, and some other eukaryotic organisms. They are considered to be intracellular endosymbiotic cyanobacteria. Examples include chloroplasts (used for photosynthesis), chromoplasts (used for pigment synthesis and storage), and leucoplasts (non-pigmented plastids that can sometimes differentiate). The event which led to permanent endosymbiosis in the Archaeplastida clade (of land plants, red algae, and green algae) probably occurred with a cyanobiont (a symbiotic cyanobacteria) related to the genus '' Gloeomargarita'', around 1.5 billion years ago. A later primary endosymbiosis event occurred in photosynthetic ''Paulinella'' amoeboids about 90–140 million years ago. This plastid belongs to the "PS-clade" (of the cyanobacteria genera ''Prochlorococcus'' and ''Synechococcus''). Secondary and tertiary endosymbiosis has also occurred, in a wid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plagiomnium Affine Laminazellen
''Plagiomnium'' is a genus of mosses in the family Mniaceae. It was formerly a part of a more encompassing genus ''Mnium'' and in 1968 Finish bryologist Timo Juhani Koponen justified splitting the genus into a number of smaller genera. Description This genus is characterized by singly placed marginal teeth. ''Plagiomnium'' are commonlyg found along shaded stream banks, seeps and springs, generally on soil with a high humus content. Species The genus ''Plagiomnium'' contains the following species: *''Plagiomnium acutum'' *'' Plagiomnium affine'' *'' Plagiomnium arbusculum'' *''Plagiomnium carolinianum'' *'' Plagiomnium ciliare'' *'' Plagiomnium cinclidioides'' *'' Plagiomnium confertidens'' *'' Plagiomnium cordatum'' *'' Plagiomnium cuspidatum'' *'' Plagiomnium drummondii'' *''Plagiomnium ecklonii'' *'' Plagiomnium elatum'' *'' Plagiomnium elimbatum'' *''Plagiomnium ellipticum'' *''Plagiomnium insigne'' *''Plagiomnium integroradiatum'' *''Plagiomnium integ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gloeomargarita Lithophora
''Gloeomargarita lithophora'' is a cyanobacterium, and is the proposed sister of the endosymbiotic plastids in the eukaryote group Archaeplastida (glaucophytes, plants, green and red algae). ''Gloeomargaritas relative would have ended up in an ancestral archaeplastid through a singular endosymbiotic event some 1900-1400 million years ago, after which it was recruited by the euglenids and some members of the SAR supergroup. The origin of plastids by endosymbiosis signifies the beginning of photosynthesis in eukaryotes, and as such their evolutionary relationship to ''Gloeomargarita lithophora'', perhaps as a direct divergent, is of high importance to the evolutionary history of photosynthesis. ''Gloeomargarita'' appears to be related to a (basal) ''Synechococcus'' branch. A similar endosymbiotic event occurred about 500 million years ago, with another ''Synechococcus'' related bacteria appearing in '' Paulinella chromatophora''. Description ''G. lithophora'' was first isolated i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prokaryotic Cells
A prokaryote () is a single-celled organism that lacks a nucleus and other membrane-bound organelles. The word ''prokaryote'' comes from the Greek πρό (, 'before') and κάρυον (, 'nut' or 'kernel').Campbell, N. "Biology:Concepts & Connections". Pearson Education. San Francisco: 2003. In the two-empire system arising from the work of Édouard Chatton, prokaryotes were classified within the empire Prokaryota. But in the three-domain system, based upon molecular analysis, prokaryotes are divided into two domains: ''Bacteria'' (formerly Eubacteria) and ''Archaea'' (formerly Archaebacteria). Organisms with nuclei are placed in a third domain, Eukaryota. In the study of the origins of life, prokaryotes are thought to have arisen before eukaryotes. Besides the absence of a nucleus, prokaryotes also lack mitochondria, or most of the other membrane-bound organelles that characterize the eukaryotic cell. It was once thought that prokaryotic cellular components within the cytopla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circular Prokaryote Chromosome
A circular chromosome is a chromosome in bacteria, archaea, mitochondria, and chloroplasts, in the form of a molecule of circular DNA, unlike the linear chromosome of most eukaryotes. Most prokaryote chromosomes contain a circular DNA molecule – there are no free ends to the DNA. Free ends would otherwise create significant challenges to cells with respect to DNA replication and stability. Cells that do contain chromosomes with DNA ends, or telomeres (most eukaryotes), have acquired elaborate mechanisms to overcome these challenges. However, a circular chromosome can provide other challenges for cells. After replication, the two progeny circular chromosomes can sometimes remain interlinked or tangled, and they must be resolved so that each cell inherits one complete copy of the chromosome during cell division. Replication The circular bacteria chromosome replication is best understood in the well-studied bacteria ''Escherichia coli'' and ''Bacillus subtilis''. Chromoso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryote
Eukaryotes () are organisms whose cells have a 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 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. This implies that there are only 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 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 phagotrophs. Their name comes from the Greek εὖ (''eu'', "well" or "good") and κάρυον (''karyon'', "nut" or "kernel"). Euka ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autotroph
An autotroph or primary producer is an organism that produces complex organic compounds (such as carbohydrates, fats, and proteins) using carbon from simple substances such as carbon dioxide,Morris, J. et al. (2019). "Biology: How Life Works", 3rd edition, W. H. Freeman. generally using energy from light (photosynthesis) or inorganic chemical reactions (chemosynthesis). They convert an abiotic source of energy (e.g. light) into energy stored in organic compounds, which can be used by other organisms (e.g. heterotrophs). Autotrophs do not need a living source of carbon or energy and are the producers in a food chain, such as plants on land or algae in water (in contrast to heterotrophs as consumers of autotrophs or other heterotrophs). Autotrophs can reduce carbon dioxide to make organic compounds for biosynthesis and as stored chemical fuel. Most autotrophs use water as the reducing agent, but some can use other hydrogen compounds such as hydrogen sulfide. The primary produ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Pigment
Biological pigments, also known simply as pigments or biochromes, are substances produced by living organisms that have a color resulting from selective color absorption. Biological pigments include plant pigments and flower pigments. Many biological structures, such as skin, eyes, feathers, fur and hair contain pigments such as melanin in specialized cells called chromatophores. In some species, pigments accrue over very long periods during an individual's lifespan. Pigment color differs from structural color in that it is the same for all viewing angles, whereas structural color is the result of selective reflection or iridescence, usually because of multilayer structures. For example, butterfly wings typically contain structural color, although many butterflies have cells that contain pigment as well. Biological pigments See conjugated systems for electron bond chemistry that causes these molecules to have pigment. * Heme/porphyrin-based: chlorophyll, bilirubin, hemocy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernst Haeckel
Ernst Heinrich Philipp August Haeckel (; 16 February 1834 – 9 August 1919) was a German zoologist, naturalist, eugenicist, philosopher, physician, professor, marine biologist and artist. He discovered, described and named thousands of new species, mapped a genealogical tree relating all life forms and coined many terms in biology, including ''ecology'', '' phylum'', ''phylogeny'', and ''Protista.'' Haeckel promoted and popularised Charles Darwin's work in Germany and developed the influential but no longer widely held recapitulation theory ("ontogeny recapitulates phylogeny") claiming that an individual organism's biological development, or ontogeny, parallels and summarises its species' evolutionary development, or phylogeny. The published artwork of Haeckel includes over 100 detailed, multi-colour illustrations of animals and sea creatures, collected in his ''Kunstformen der Natur'' ("Art Forms of Nature"), a book which would go on to influence the Art Nouveau artistic mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andreas Franz Wilhelm Schimper
Andreas Franz Wilhelm Schimper (12 May 1856 – 9 September 1901) was a German botanist and phytogeographer who made major contributions in the fields of histology, ecology and plant geography. He travelled to South East Asia and the Caribbean as part of the 1899 deep-sea expedition. He coined the terms tropical rainforest and sclerophyll and is commemorated in numerous specific names. Biography Schimper was born in Strassburg, (present day Strasbourg, France), into a family of eminent scientists. His father Wilhelm Philippe Schimper (1808-1880) was Director of the Natural History Museum in the same town, Professor of Geology, and a leading bryologist. His father's cousin was Georg Wilhelm Schimper (1804-1878), prominent collector and explorer in Arabia and North Africa; the naturalist Karl Friedrich Schimper was also a relative. Schimper studied at the University of Strassburg from 1874 to 1878, acquiring a Ph.D. He then worked in Lyon, and in 1880 travelled to the United ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kleptoplasty
Kleptoplasty or kleptoplastidy is a symbiosis, symbiotic phenomenon whereby plastids, notably chloroplasts from algae, are sequestered by host organisms. The word is derived from ''Kleptes'' (κλέπτης) which is Greek language, Greek for thief. The alga is eaten normally and partially digested, leaving the plastid intact. The plastids are maintained within the host, temporarily continuing photosynthesis and benefiting the predator. The term was coined in 1990 to describe chloroplast symbiosis. Ciliates ''Mesodinium rubrum'' is a ciliate that steals chloroplasts from the cryptomonad ''Geminigera cryophila''. ''M. rubrum'' participates in additional endosymbiosis by transferring its plastids to its predators, the dinoflagellate planktons belonging to the genus ''Dinophysis''. Karyoklepty is a related process in which the nucleus of the prey cell is kept by the predator as well. This was first described in 2007 in ''M. rubrum''. Dinoflagellates The stability of transient ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroplast
A chloroplast () is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, and stores it in the energy-storage molecules ATP and NADPH while freeing oxygen from water in the cells. The ATP and NADPH is then used to make organic molecules from carbon dioxide in a process known as the Calvin cycle. Chloroplasts carry out a number of other functions, including fatty acid synthesis, amino acid synthesis, and the immune response in plants. The number of chloroplasts per cell varies from one, in unicellular algae, up to 100 in plants like ''Arabidopsis'' and wheat. A chloroplast is characterized by its two membranes and a high concentration of chlorophyll. Other plastid types, such as the leucoplast and the chromoplast, contain little chlorophyll and do not carry out photosynthesis. Chloroplasts are highly dynamic—they circulat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synechococcus
''Synechococcus'' (from the Greek ''synechos'', in succession, and the Greek ''kokkos'', granule) is a unicellular cyanobacterium that is very widespread in the marine environment. Its size varies from 0.8 to 1.5 µm. The photosynthetic coccoid cells are preferentially found in well–lit surface waters where it can be very abundant (generally 1,000 to 200,000 cells per ml). Many freshwater species of ''Synechococcus'' have also been described. The genome of ''S. elongatus'' strain PCC7002 has a size of 3,008,047 bp, whereas the oceanic strain WH8102 has a genome of size 2.4 Mbp. Introduction ''Synechococcus'' is one of the most important components of the prokaryotic autotrophic picoplankton in the temperate to tropical oceans. The genus was first described in 1979, and was originally defined to include "small unicellular cyanobacteria with ovoid to cylindrical cells that reproduce by binary traverse fission in a single plane and lack sheaths". This definition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
