This required a mastery of the integuments of war, just as a jazz musician masters his musical instrument.
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Very little is known about the early evolution of insects that mooch off of "integuments," protective layers such as feathers, skin, or scales, because parasites are normally too fragile to be preserved by the fossilization process.
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In plant ovules, the chalaza is located opposite the micropyle opening of the integuments. It is the tissue where the integuments and nucellus are joined. Nutrients from the plant travel through vascular tissue in the funiculus and outer integument through the chalaza into the nucellus. During the development of the embryo sac inside a flowering plant ovule, the three cells at the chalazal end become the antipodal cells.
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The sea-slug has a small pleural tooth 54μ wide, described by Labbé as "a bit like P. verruclata". Their size ranged from 10 to 5 mm in length and they have a very contacted body, almost globular. They also have thin integuments and a slightly pigmented pleural cavity.
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Three days before adults emerge, developing parasite spores can be seen through their pupal integuments. The adult butterflies emerge covered with spores, mostly on their abdomens. Parasites do not continue to replicate on adult butterflies and spores must be eaten by larvae before they can cause new infections.
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The seed coat develops from the maternal tissue, the integuments, originally surrounding the ovule. The seed coat in the mature seed can be a paper-thin layer (e.g. peanut) or something more substantial (e.g. thick and hard in honey locust and coconut), or fleshy as in the sarcotesta of pomegranate.
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The maturing ovule undergoes marked changes in the integuments, generally a reduction and disorganization but occasionally a thickening. The seed coat forms from the two integuments or outer layers of cells of the ovule, which derive from tissue from the mother plant, the inner integument forms the tegmen and the outer forms the testa. (The seed coats of some monocotyledon plants, such as the grasses, are not distinct structures, but are fused with the fruit wall to form a pericarp.) The testae of both monocots and dicots are often marked with patterns and textured markings, or have wings or tufts of hair. When the seed coat forms from only one layer, it is also called the testa, though not all such testae are homologous from one species to the next.
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The funiculus abscisses (detaches at fixed point – abscission zone), the scar forming an oval depression, the hilum. Anatropous ovules have a portion of the funiculus that is adnate (fused to the seed coat), and which forms a longitudinal ridge, or raphe, just above the hilum. In bitegmic ovules (e.g. Gossypium described here) both inner and outer integuments contribute to the seed coat formation.
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The pollen grains are spheroidal and reticulate (net like pattern), with individual brochi (lumina within reticulations) of 4–5 μm. ; Fruit and seeds The capsule is obovoid to globose, loculicidal and six-angled, sometimes with wings. The seeds are flattened with a marginal wing, the seed coat made out of both integuments, but the testa is thin and the endosperm lacks starch. The embryo is small.
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In most flowering plants, the pollen tube enters the ovule through the micropyle opening in the integuments for fertilization (porogamy). In chalazogamous fertilization, the pollen tubes penetrate the ovule through the chalaza rather than the micropyle opening. Chalazogamy was first discovered in monoecious plant species of the family Casuarinaceae by Melchior Treub, but has since then also been observed in others, for example in pistachio and walnut.
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The female gametophyte, the megagametophyte, that participates in double fertilization in angiosperms which is haploid is called the embryo sac. This develops within an ovule, enclosed by the ovary at the base of a carpel. Surrounding the megagametophyte are (one or) two integuments, which form an opening called the micropyle. The megagametophyte, which is usually haploid, originates from the (usually diploid) megaspore mother cell, also called the megasporocyte.
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Ji, S., Ji, Q., Lu J., and Yuan, C. (2007). "A new giant compsognathid dinosaur with long filamentous integuments from Lower Cretaceous of Northeastern China." Acta Geologica Sinica, 81(1): 8-15 There have been signs of basic feather structures on Juravenator, but evidence of this is still not definite. Samples of Juravenator skin show scales instead of feathers, leading into debates about Juravenator’s place within the family Compsognathidae.
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The nucellus (plural: nucelli) is part of the inner structure of the ovule, forming a layer of diploid (sporophytic) cells immediately inside the integuments. It is structurally and functionally equivalent to the megasporangium. In immature ovules, the nucellus contains a megasporocyte (megaspore mother cell), which undergoes sporogenesis via meiosis. In the megasporocyte of Arabidopsis thaliana, meiosis depends on the expression of genes that facilitate DNA repair and homologous recombination.
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Pygopleurus vulpes can reach a length of .Beetles and Coleopterologists The males of these beetles are completely covered by long hairs. They do not show variability of integuments and setae, but their color ranges from the common straw-yellow color to reddish and dark orange color.Maurizio Bollino and Gianpaolo Ruzzante COROLOGICAL NOTES ON SOME SPECIES OF PYGOPLEURUS (COLEOPTERA: GLAPHYRIDAE) FROM THE GREEK ISLAND OF LESBOS In the females the pronotum is greenish and the brown elytrae remain visible.
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Many insects and some mites are specialized to feed on pollen, and are called palynivores. In non-flowering seed plants, pollen germinates in the pollen chamber, located beneath the micropyle, underneath the integuments of the ovule. A pollen tube is produced, which grows into the nucellus to provide nutrients for the developing sperm cells. Sperm cells of Pinophyta and Gnetophyta are without flagella, and are carried by the pollen tube, while those of Cycadophyta and Ginkgophyta have many flagella.
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The two men made their discoveries independent of each other, Navashin in 1898 and Guignard in 1899.Reproduction and development in flowering plants Comptes Rendus de l'Académie des Sciences, Série III. 2001 Jun;324(6):517-21 He also introduced a new method for detecting the presence of hydrocyanic acid in plants.Bulletin of Miscellaneous Information by Trinidad Botanical Department In addition, he conducted significant research on the origin and structure of integuments for a large number of seeds.
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Representatives of the lycopods have survived to the present day. By the end of the Devonian period, several groups, including the lycopods, sphenophylls and progymnosperms, had independently evolved "megaspory" – their spores were of two distinct sizes, larger megaspores and smaller microspores. Their reduced gametophytes developed from megaspores retained within the spore-producing organs (megasporangia) of the sporophyte, a condition known as endospory. Seeds consist of an endosporic megasporangium surrounded by one or two sheathing layers (integuments).
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When first > discovered the arrows were in a sort of quiver of bark, which fell in pieces > when exposed to the air. > The skull is much decayed, but the teeth are sound and apparently of a young > man. The pelvis is much decayed and the smaller bones of the lower > extremities are gone. > The integuments of the right knee, for four or five inches above and below, > are in good preservation, apparently the size and shape of life, although > quite black.
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The ovule is anatropous in orientation and has two integuments (bitegmic), the micropyle (opening) being formed from the inner integument, while the nucellus is small. The embryo sac or megagametophyte is tetrasporic, in which all four megaspores survive. The style is trilobate to trifid (in 3 parts) and the surface of the stigma is wet. ; Androecium Stamens are six, in two trimerous whorls of three, and diplostemonous (outer whorl of stamens opposite outer tepals and the inner whorl opposite inner tepals).
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"A new giant compsognathid dinosaur with long filamentous integuments from Lower Cretaceous of Northeastern China." Acta Geologica Sinica, 81(1): 8-15 The holotype, JMP-V-05-8-01, was discovered at Hengdaozi, in Sihetun, in Liaoning Province, from the Jianshangou Beds of the Yixian Formation dating from the Barremian-Aptian, about 125 million years old. It consists of a nearly complete skeleton with skull, compressed on a single plate, of an adult individual. Extensive remains of protofeathers have been preserved.
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Gonatopus is a genus of solitary wasps of the family Dryinidae, sometimes called hump-backed pincer wasps. The wingless females have large scissor-like appendages at the tips of the front legs which are used to catch the leafhopper grubs which act as hosts to the larvae of these wasps. The larva consumes the leafhopper grub from the inside. An indication that a leafhopper is hosting a grub is a cyst of accumulated shed integuments which surround and protect the growing wasp larva.
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It was not posed in a standing posture, which suggests that it was severed from a fresh specimen, not a mounted one. By 1896 it was mentioned as being without its integuments, and only the bones are believed to remain today, though its present whereabouts are unknown. The Copenhagen skull (specimen ZMUC 90-806) is known to have been part of the collection of Bernardus Paludanus in Enkhuizen until 1651, when it was moved to the museum in Gottorf Castle, Schleswig.
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The front of the pelvis was adapted to support the enlarged belly. Therizinosaurs are known to have had simple, primitive feathers as evidenced by fossils of the basal (or "primitive") genera Beipiaosaurus—the second-known non-bird dinosaur preserved with such integuments after Sinosauropteryx—and Jianchangosaurus. Since most therizinosaurs are incompletely known, it is uncertain how many of the anatomical features that are used to distinguish Segnosaurus are widespread among the group; many genera cannot be directly compared because the equivalent bones are not preserved.
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In gymnosperms, the megagametophyte consists of around 2000 nuclei and forms archegonia, which produce egg cells for fertilization. In flowering plants, the megagametophyte (also referred to as the embryo sac) is much smaller and typically consists of only seven cells and eight nuclei. This type of megagametophyte develops from the megaspore through three rounds of mitotic divisions. The cell closest to the micropyle opening of the integuments differentiates into the egg cell, with two synergid cells by its side that are involved in the production of signals that guide the pollen tube.
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Sereno, P.C. (2012). pp. 161–162. The family contains some of the smallest known ornithischian dinosaurs – the North American Fruitadens, for example, reached a length of only . Following the description of the related Tianyulong in 2009, which was preserved with hundreds of long, filamentous integuments (sometimes compared to bristles) from neck to tail, Heterodontosaurus has also been depicted with such structures, for example in publications by the palaeontologists Gregory S. Paul and Paul Sereno. Sereno has stated that a heterodontosaur may have looked like a "nimble two-legged porcupine" in life.
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The megagametophyte typically develops a small number of cells, including two special cells, an egg cell and a binucleate central cell, which are the gametes involved in double fertilization. The central cell, once fertilized by a sperm cell from the pollen becomes the first cell of the endosperm, and the egg cell once fertilized become the zygote that develops into the embryo. The gap in the integuments through which the pollen tube enters to deliver sperm to the egg is called the micropyle. The stalk attaching the ovule to the placenta is called the funiculus.
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Seeds are the product of the ripened ovule, after fertilization by pollen and some growth within the mother plant. The embryo is developed from the zygote and the seed coat from the integuments of the ovule. Seeds have been an important development in the reproduction and success of gymnosperm and angiosperm plants, relative to more primitive plants such as ferns, mosses and liverworts, which do not have seeds and use water-dependent means to propagate themselves. Seed plants now dominate biological niches on land, from forests to grasslands both in hot and cold climates.
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Apparently, the grouping of tardigrades with nematodes found in a number of molecular studies is a long branch attraction artifact. Within the arthropod group (called panarthropoda and comprising onychophora, tardigrades and euarthropoda), three patterns of relationship are possible: tardigrades sister to onychophora plus arthropods (the lobopodia hypothesis); onychophora sister to tardigrades plus arthropods (the tactopoda hypothesis); and onychophora sister to tardigrades. Recent analyses indicate that the panarthropoda group is monophyletic, and that tardigrades are a sister group of Lobopodia, the lineage consisting of arthropods and Onychophora. The minute sizes of tardigrades and their membranous integuments make their fossilization both difficult to detect and highly unusual.
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He describes the standard arrangement in angiosperms—the nucellus joined by the chalaza to the integuments, which surround the nucellus except at the micropyle, through which the pollen tubes enter. David Mabberley describes this section as "a remarkably clear exposition of one of the most intricate and misunderstood areas of developmental anatomy in higher plants." The third part is a discussion of the "female flower" of cycads and conifers. In it, Brown sets out for the first time the fundamental difference between angiosperms and gymnosperms; namely, that pollen grains are drawn into the ovule in gymnosperms, whereas in angiosperms, contact is via pollen tubes.
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Another possibility may arise from somatic fusion: there are multicellular life-styles where there are few if any physical barriers to the intermingling of cells (for example: sponges, fungal mycelia) and even among organisms that have evolved physical integuments representing a first line of defense against invasion, opportunities for cellular exchange occur. Witness, for example, the spread of devil facial tumour disease among Tasmanian devils and transmissible venereal tumor in dogs. In metazoans, defense against disruption of the multicellular life style by such cheaters takes two major forms. First, a consistent feature of the multicellular life cycle is the interposition of a unicellular phase, even among organisms whose major mode of propagation may be via many-celled vegetative propagules.
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Ovule structure (anatropous) 1: nucleus 2: chalaza 3: funiculus 4: raphe Ovule orientation may be anatropous, such that when inverted the micropyle faces the placenta (this is the most common ovule orientation in flowering plants), amphitropous, campylotropous, or orthotropous (anatropous are common and micropyle is in downward position and chalazal end in on the upper position hence, in amphitropous the anatropous arrangement is tilted 90 degrees and in orthotropus it is completely inverted) . The ovule appears to be a megasporangium with integuments surrounding it. Ovules are initially composed of diploid maternal tissue, which includes a megasporocyte (a cell that will undergo meiosis to produce megaspores). Megaspores remain inside the ovule and divide by mitosis to produce the haploid female gametophyte or megagametophyte, which also remains inside the ovule.
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Some animals change color in changing environments seasonally, as in ermine and snowshoe hare, or far more rapidly with chromatophores in their integuments, as in chameleon and cephalopods such as squid. Countershading, the use of different colors on upper and lower surfaces in graduating tones from a light belly to a darker back, is common in the sea and on land. It is sometimes called Thayer's law, after the American artist Abbott Handerson Thayer, who published a paper on the form in 1896 that explained that countershading paints out shadows to make solid objects appear flat, reversing the way that artists use paint to make flat paintings contain solid objects. Where the background is brighter than is possible even with white pigment, counter-illumination in marine animals, such as squid, can use light to match the background.
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The pollen grains are dispersed by the wind to the female, ovulate cone that is made up of many overlapping scales (sporophylls, and thus megasporophylls), each protecting two ovules, each of which consists of a megasporangium (the nucellus) wrapped in two layers of tissue, the integument and the cupule, that were derived from highly modified branches of ancestral gymnosperms. When a pollen grain lands close enough to the tip of an ovule, it is drawn in through the micropyle ( a pore in the integuments covering the tip of the ovule) often by means of a drop of liquid known as a pollination drop. The pollen enters a pollen chamber close to the nucellus, and there it may wait for a year before it germinates and forms a pollen tube that grows through the wall of the megasporangium (=nucellus) where fertilisation takes place. During this time, the megaspore mother cell divides by meiosis to form four haploid cells, three of which degenerate.
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