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Pit (fruit)
A pyrena () or pyrene, commonly called a pit or stone, is the fruitstone within a drupe or drupelet produced by the ossification of the endocarp or lining of the fruit. It consists of a hard endocarp tissue surrounding one or more seeds (also called the "kernel"). The hardened endocarp which constitutes the pyrene provides a protective physical barrier around the seed, shielding it from pathogens and herbivory. While many drupes are monopyrenous, containing only one pyrene, pome-type fruit with a hard, stony (rather than leathery) endocarp are typically polypyrenous drupes, containing multiple pyrenes. Development The hardening of the endocarp of a developing drupe occurs via secondary cell wall formation and lignification. The biopolymer lignin, also found in wood, provides a structure within secondary cell walls which supports the polymerisation of cellulose and hemicellulose; together these polymers provide the endocarp with tensile strength and stiffness. Further hardenin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drupe Fruit Diagram
In botany, a drupe (or stone fruit) is a type of fruit in which an outer fleshy part ( exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the ''pip'' (UK), ''pit'' (US), ''stone'', or '' pyrena'') of hardened endocarp with a seed (''kernel'') inside. Drupes do not split open to release the seed, i.e., they are indehiscent. These fruits usually develop from a single carpel, and mostly from flowers with superior ovaries ( polypyrenous drupes are exceptions). The definitive characteristic of a drupe is that the hard, woody ( lignified) stone is derived from the ovary wall of the flower. In an aggregate fruit, which is composed of small, individual drupes (such as a raspberry), each individual is termed a drupelet, and may together form an aggregate fruit. Such fruits are often termed ''berries'', although botanists use a different definition of ''berry''. Other fleshy fruits may have a stony enclosure that comes from the seed coat surrounding the seed, but s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymerisation
In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. There are many forms of polymerization and different systems exist to categorize them. In chemical compounds, polymerization can occur via a variety of reaction mechanisms that vary in complexity due to the functional groups present in the reactants and their inherent steric effects. In more straightforward polymerizations, alkenes form polymers through relatively simple radical reactions; in contrast, reactions involving substitution at a carbonyl group require more complex synthesis due to the way in which reactants polymerize. As alkenes can polymerize in somewhat straightforward radical reactions, they form useful compounds such as polyethylene and polyvinyl chloride (PVC), which are produced in high tonnages each year due to their usefulness in m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nut (fruit)
A nut is a fruit consisting of a hard or tough nutshell protecting a kernel which is usually edible. In general usage and in a culinary sense, many dry seeds are called nuts, but in a botanical context, "nut" implies that the shell does not open to release the seed (Dehiscence (botany), indehiscent). Most seeds come from fruits that naturally free themselves from the shell, but this is not the case in nuts such as hazelnuts, chestnuts, and acorns, which have hard shell walls and originate from a compound ovary. Definition A seed is the mature fertilised ovule of a plant; it consists of three parts, the embryo which will develop into a new plant, stored food for the embryo, and a protective seed coat. Botany, Botanically, a nut is a fruit with a woody pericarp developing from a syncarpous gynoecium. Nuts may be contained in an Bract#Involucral bracts, involucre, a cup-shaped structure formed from the flower bracts. The involucre may be scaly, spiny, leafy or tubular, depending ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Locule
A locule (: locules) or loculus (; : loculi) is a small cavity or compartment within an organ or part of an organism (animal, plant, or fungus). In angiosperms (flowering plants), the term ''locule'' usually refers to a chamber within an ovary (gynoecium or carpel) of the flower and fruits. Depending on the number of locules in the ovary, fruits can be classified as (uni-locular), , , or . The number of locules present in a gynoecium may be equal to or less than the number of carpels. The locules contain the ovules or seeds. The term may also refer to chambers within anthers containing pollen. In ascomycetous fungi, locules are chambers within the hymenium The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in oth ... in which the perithecia develop. References Plant anatomy Plant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elaeocarpus Ganitrus
''Elaeocarpus angustifolius'' is a species of flowering plant in the family Elaeocarpaceae and occurs from India to New Caledonia and northern Australia. Common synonyms are ''E. ganitrus'' and ''E. sphaericus''. It is a large evergreen tree, often with buttress roots, and has leaves with wavy serrations, creamy white flowers and more or less spherical bright blue drupe fruit. In English, the tree is known as utrasum bean tree in India. In Sri Lanka recorded names are woodenbegar and Indian bead tree. It is simply known as elaeocarpus in the Northern Territory of Australia. Other names used for this tree in Australia are Indian oil fruit and genitri. In Hawaii it (or the possible synonym ''E. grandis'') is known as a blue marble tree. In India, the cleaned pits of the fruit of this tree are known as ''rudraksha'' (from Sanskrit: ', meaning "Rudra's teardrops" or "eyes") and are widely used as prayer beads, particularly in Hinduism. ''Rudraksha'' might be produced by more than o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crataegus Punctata
''Crataegus punctata'' is a species of hawthorn known by the common names dotted hawthorn or white haw that is native to most of the eastern United States and eastern Canada. While some sources claim it is the state flower of Missouri, the actual legislation does not identify an exact species. Furthermore, the Missouri Department of Conservation asserts the '' Crataegus mollis'' was specifically designated as the state flower. Description Although many North American hawthorns are polyploid and reproduce by apomixis, this species is apparently diploid and sexual, at least throughout Ontario, Canada. The name white haw refers to its distinctive pale (grey) bark, which is particularly noticeable in the winter landscape. The plant is a bush or small tree to about 7 meters in height and very thorny, particularly on the trunk. The flower has three to five styles and approximately 20 stamens, and the fruit is a pome-type polypyrenous drupe In botany, a drupe (or stone fruit) is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peach
The peach (''Prunus persica'') is a deciduous tree first domesticated and Agriculture, cultivated in China. It bears edible juicy fruits with various characteristics, most called peaches and the glossy-skinned, non-fuzzy varieties called nectarines. Peaches and #Nectarines, nectarines are the same species, though they are regarded commercially as different fruits. The tree is regarded as handsome and is planted in gardens for its springtime blooms in addition to fruit production. The peach tree is relatively short lived, usually not exceeding twenty years of age. However, the peach fruit is regarded as a symbol of longevity in several East Asian cultures. The specific name ''persica'' refers to its widespread cultivation in Persia (modern-day Iran), from where it was transplanted to Europe and in the 16th century to the Americas. It belongs to the genus ''Prunus'', which also includes the cherry, apricot, almond, and plum, and which is part of the Rosaceae, rose family. The p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeology
Archaeology or archeology is the study of human activity through the recovery and analysis of material culture. The archaeological record consists of Artifact (archaeology), artifacts, architecture, biofact (archaeology), biofacts or ecofacts, archaeological site, sites, and cultural landscapes. Archaeology can be considered both a social science and a branch of the humanities. It is usually considered an independent academic discipline, but may also be classified as part of anthropology (in North America – the four-field approach), history or geography. The discipline involves Survey (archaeology), surveying, Archaeological excavation, excavation, and eventually Post excavation, analysis of data collected, to learn more about the past. In broad scope, archaeology relies on cross-disciplinary research. Archaeologists study human prehistory and history, from the development of the first stone tools at Lomekwi in East Africa 3.3 million years ago up until recent decades. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biomineralisation
Biomineralization, also written biomineralisation, is the process by which living organisms produce minerals, often resulting in hardened or stiffened '' mineralized tissues''. It is an extremely widespread phenomenon: all six taxonomic kingdoms contain members that can form minerals, and over 60 different minerals have been identified in organisms. Examples include silicates in algae and diatoms, carbonates in invertebrates, and calcium phosphates and carbonates in vertebrates. These minerals often form structural features such as sea shells and the bone in mammals and birds. Organisms have been producing mineralized skeletons for the past 550 million years. Calcium carbonates and calcium phosphates are usually crystalline, but silica organisms (such as sponges and diatoms) are always non-crystalline minerals. Other examples include copper, iron, and gold deposits involving bacteria. Biologically formed minerals often have special uses such as magnetic sensors in magnetota ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stiffness
Stiffness is the extent to which an object resists deformation in response to an applied force. The complementary concept is flexibility or pliability: the more flexible an object is, the less stiff it is. Calculations The stiffness, k, of a body is a measure of the resistance offered by an elastic body to deformation. For an elastic body with a single degree of freedom (DOF) (for example, stretching or compression of a rod), the stiffness is defined as k = \frac where, * F is the force on the body * \delta is the displacement produced by the force along the same degree of freedom (for instance, the change in length of a stretched spring) Stiffness is usually defined under quasi-static conditions, but sometimes under dynamic loading. In the International System of Units, stiffness is typically measured in newtons per meter (N/m). In Imperial units, stiffness is typically measured in pounds (lbs) per inch. Generally speaking, deflections (or motions) of an infinitesima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tensile Strength
Ultimate tensile strength (also called UTS, tensile strength, TS, ultimate strength or F_\text in notation) is the maximum stress that a material can withstand while being stretched or pulled before breaking. In brittle materials, the ultimate tensile strength is close to the yield point, whereas in ductile materials, the ultimate tensile strength can be higher. The ultimate tensile strength is usually found by performing a tensile test and recording the engineering stress versus strain. The highest point of the stress–strain curve is the ultimate tensile strength and has units of stress. The equivalent point for the case of compression, instead of tension, is called the compressive strength. Tensile strengths are rarely of any consequence in the design of ductile members, but they are important with brittle members. They are tabulated for common materials such as alloys, composite materials, ceramics, plastics, and wood. Definition The ultimate tensile strength ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemicellulose
A hemicellulose (also known as polyose) is one of a number of heteropolymers (matrix polysaccharides), such as arabinoxylans, present along with cellulose in almost all embryophyte, terrestrial plant cell walls. Cellulose is crystalline, strong, and resistant to hydrolysis. Hemicelluloses are branched, shorter in length than cellulose, and also show a propensity to crystallize. They can be hydrolyzed by dilute acid or Base (chemistry), base as well as a myriad of Cellulase, hemicellulase enzymes. Composition Diverse kinds of hemicelluloses are known. Important examples include xylan, glucuronoxylan, arabinoxylan, glucomannan, and xyloglucan. Hemicelluloses are polysaccharides often associated with cellulose, but with distinct compositions and structures. Whereas cellulose is derived exclusively from glucose, hemicelluloses are composed of diverse sugars, and can include the five-carbon sugars xylose and arabinose, the six-carbon sugars glucose, mannose and galactose, and the si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
