1190 résultats pour "planta"

• New Brunswick - Canadian History.

  Grand Lake, the largest lake in New Brunswick, is in the lowlands, east of Fredericton. Most other lakes are located in the northern and southwestern parts of NewBrunswick. D Climate New Brunswick has a continental climate that is moderated by maritime influences in the coastal areas. As a result, coastal regions are slightly warmer in the winter andslightly cooler in the summer than are interior regions. Annual temperature variations are large, with the January mean usually at least 25 to 28°C...

• Turkey - country.

  has a general elevation of 900 to 1,500 m (3,000 to 5,000 ft) above sea level. The eastern highlands region is the most mountainous and rugged portion of Turkey; Mount Ararat (Ağrı Da ğı) is the highest peak in the country at 5,165 m (16,945ft). Many Christians and Jews believe it to be the same Mount Ararat mentioned in the Bible as the place where Noah’s ark came to rest. The eastern highlands are thesource for both the Tigris (Dicle) and Euphrates (Fir āt)—two of southwestern Asia’s principal...

• Le désert exerce une étrange attirance.

  de formes d'accumulation (cônes de déjection, terrasses caillouteuses ou limoneuses). Le travail du froid explique, d'autre part, la présence de coulées de blocs ou de cirques glaciaires ; celui du vent, l'existence de vieilles dunes roses et de dépressions fermées. Tous ces modelés sont des héritages des périodes glaciaires et interglaciaires du quaternaire, fidèlement illustrées d'ailleurs par les poissons, les girafes ou les hippopotames gravés sur les rochers par les hommes préhistoriques. S...

• Présentation d'une plante de manière philosophique

• Ecosystem.

  work. The tiny bacteria and fungi feed upon the remains of the salmon. They break down the salmon intochemical nutrients. Nutrients from the salmon go into the soil. The roots of plants along the riverbank take up the nutrients. They use the nutrients to make food. Inthis way, nutrients get recycled back through the ecosystem. WHAT CAN HARM AN ECOSYSTEM? Any change in one living or nonliving part of an ecosystem can cause changes in other parts. Droughts,storms, and fires can change ecosystems....

• Le climat et la végétation

  Blé eoue la neige (Martlnerle-Fotogram). SI les céréale~ del réglons tempéréee eont vemalls6e1 par le froid, la neige le1 protège de1 températ\jree exce11lve1. · Lee longues et large~ feuilles du bananier, déchirées en lanlé·. ree par le vent, facilitent l'évaporation de l'eau qu'li pulle abondamment. (Holmès-Lebel). absolument nécessaire pour que les fonctions vitales s'accomplissent pendant les jours chauds : c'est pendant cette périod...

• biotechnologies - sciences et techniques.

  cours d’expérimentation comme celles ayant la propriété de sécréter naturellement leurs propres insecticides ou des gènes de qualité contrôlant la maturation et la conservation. Lorsque tous les gènes mis en jeu seront identifiés, les plantes transgéniques pourront peut-être résister au froid, au gel, à la sécheresse et à des sols salés. Pour justifier la dissémination des organismes transgéniques, les partisans des OGM brandissent l’argument selon lequel la population va croître davantage que l...

• Définition du terme: CRYPT(O)-, (CRYPT-, CRYPTO-) élément préfixe.

  l'Académie Française, Compléments 1842, DICTIONNAIRE UNIVERSEL DE LA LANGUE FRANÇAISE (LOUIS-NICOLAS BESCHERELLE) 1845, Grand dictionnaire universel du XIXe. siècle (Pierre Larousse)-Larousse du xxe. siècle en six volumes, DICTIONNAIRE ENCYCLOPÉDIQUE QUILLET 1965) cryptolépide , cryptolépis (du grec ???pt?? « caché » et ? ep?? , ?d?? « enveloppe, coquille »), substantif féminin. " Arbrisseau volubile à feuilles opposées, veinées en dessous, à fleurs en corymbes, originaire des tropiques et dont...

• La reproduction végétale LA REPRODUCTION VÉGÉTALE Reproduction ou procréation ?

  La reproduction végétale 2) La pollinisation Quand la fleur s’épanouit, les étamines mûrissent et, à un moment, leurs anthères s’ouvrent et libèrent les grains de pollen . Les grains de pollen peuvent tomber directement s ur le pistil de la fleur ou être transportés sur une autre fleur par le vent ou par un animal (insecte le plus souvent). Il existe 3 cas :  Certaines fleurs peuvent s’autopolliniser, càd être fécondées par leurs propres grains de pollen . On pa...

• LES EPICES

  Les épices La noix de muscade est couramment ..,.._ utilisée dans les desserts. En revanche, la membrane rouge qui la recouvre donne un goût très relevé à certains plats salés. La vanille est notamment utilisée pour parfu­ mer les gâteaux, le chocolat et les glaces. Il s'agit de la racine d'une orchidée originaire d'Amé­ rique du Sud. Les Aztèques parfumaient déjà le chocolat chaud avec cette plante. De nos jours, les premiers producteurs sont le Mexi...

• Nuclear Weapons.

  Regardless of the method used to attain a supercritical assembly, the chain reaction proceeds for about a millionth of a second, liberating vast amounts of heat energy.The extremely fast release of a very large amount of energy in a relatively small volume causes the temperature to rise to tens of millions of degrees. The resultingrapid expansion and vaporization of the bomb material causes a powerful explosion. VI PRODUCTION OF FISSILE MATERIAL Much experimentation was necessary to make the p...

• Fire - chemistry.

  were usually natural caves. Eventually people learned to dip branches in pitch to form torches. They created crude lamps by filling a hollowed out piece of stone withmoss soaked in oil or tallow (a substance derived from animal fat). By cooking with fire, prehistoric people made the meat of the animals they killed more palatable and digestible. They learned to preserve meat by smoking it over a fire,vastly decreasing the danger of periodic starvation. Cooking also enabled them to add some for...

• Northwest Territories - Geography.

  million years ago by the severe bending (folding) and faulting (breaking) of sedimentary rock that was once part of the Interior Plains. During the Wisconsin Ice Age,alpine glaciers covered the Cordillera, and the movement of the glaciers created razor-sharp peaks and ridges in these mountains. The moving glaciers also createdbroad U-shaped valleys. To the east of the Interior Plains, the ancient rocks of the Canadian Shield are exposed at the Earth’s surface, resulting in a rough, rolling terra...

• Northwest Territories - Canadian History.

  million years ago by the severe bending (folding) and faulting (breaking) of sedimentary rock that was once part of the Interior Plains. During the Wisconsin Ice Age,alpine glaciers covered the Cordillera, and the movement of the glaciers created razor-sharp peaks and ridges in these mountains. The moving glaciers also createdbroad U-shaped valleys. To the east of the Interior Plains, the ancient rocks of the Canadian Shield are exposed at the Earth’s surface, resulting in a rough, rolling terra...

• South Africa - country.

  The major soil zones are conditioned largely by climatic factors. In the semiarid north and west, soils are alkaline and poorly developed. In the southern part of WesternCape Province, rain falls mostly in the winter months, and soils there form slowly and are generally thin and immature. The moderate temperatures and summer rainfallof the High Veld and eastern coastal areas create conditions for more productive organic decomposition, leading to dark, fertile soils, or chernozems, similar to tho...

• Le calendrier du jardinier

  -~--- ----------- Janvier: la fin d'une saison Pour le jardinage, le premier janvier est la fin de l'année , car c'est le printemps qu'on considère com­ me le début des travaux. Mais, en janvier , certaines plantes se mettent à fleurir: les perce-neige, les éranthis, quelques primevères , les héliotropes d'hi­ ver avec leur odeur délicieuse. Une promenade dans le jardin par un jour ensoleillé de janvier vous montrera bien des travaux à fai...

• Économie LES SOLS

  Les sols ! Un des traits majeurs des paysages A modernes est le développement de l'urbanisme. À la fin du xv11f siècle, la région de Millbank-on-the-Thames, en Angleterre, était semi-rurale (à gauche), elle fait maintenant partie du centre de Londres (à droite). Quelques semences réussissent mieux dans . certains sols. Ainsi, Je blé demande un sol fertile et argileux, tandis que J'orge se contente d'un sol plus léger et plus sableux. Quant aux pom...

• sols, travail des - agriculture et agroalimentaire.

  La pollution du sol correspond à l’accumulation de composés toxiques : produits chimiques, sels, matières radioactives ou agents pathogènes qui, tous, ont des effets nocifssur la croissance des plantes et la santé des animaux. L’utilisation accrue d’engrais et de nombreux produits insecticides et fongicides après la fin de la Seconde Guerremondiale est, depuis les années 1960, source d’inquiétude sur l’état des sols. Certes, l’application d’engrais contenant les principaux éléments nutritifs, à...

• Jardinería - ciencias de la naturaleza.

  frecuente la utilización de plantas procedentes de otros países. Los romanos, gracias a su organización social, y partiendo como modelo de las villas rústicas, dedicadas alcultivo de hortalizas, crearon las villas urbanas rodeadas de jardín. La casa se situaba en el lugar más alto y a sus pies se extendían las terrazas con sus plantas y diferentesconstrucciones. El conjunto continuaba siendo muy geométrico. Jardines de VersallesAndré Le Nôtre proyectó los jardines que rodean el palacio de Versal...

• Muséum national d'histoire naturelle [MNHN] - sciences et techniques.

  3. 4 Les instituts de botanique et d’écologie – Le Centre d’écologie générale de Brunoy (Essonne), abrite deux équipes de recherche en écologie forestière et stratégie adaptative des organismes vivants. – Le Jardin botanique exotique de Menton (Alpes-Maritimes), créé vers 1895, enrichi d’essences nouvelles, subtropicales et tropicales, de végétaux rares et de plantes alimentaires, est aussi un lieu de recherches portant sur l’acclimatation de ces végétaux et l’histoire des paysages méditerranée...

• Le thème des fleurs et plantes en art

• Los insectos - (exposé gratuit en espagnol).

  LOS INSECTOS Y LOS SERES HUMANOS Algunos insectos son perjudiciales porque pueden dañar los cultivos. El escarabajo de la patata se alimenta de las hojas de esa planta.La procesionaria es una oruga que se come las hojas de los pinos. Otros insectos, como mosquitos, moscas o pulgas, pueden transmitirenfermedades a los seres humanos. Por ejemplo, algunos mosquitos, cuando pican a una persona para alimentarse de su sangre,pueden transmitirle el microorganismo que origina la malaria. Sin embargo, la...

• les mousses et leurs proches cousines les hépatiques (Exposé – SVT – Collège/Lycée)

  gamétophytes. Les petites poivrières qui se dressent sur les mousses à certaines périodes de l'année con­ tiennent les spores qui seront répan­ dues dans l'atmosphère quand elles seront mûres, transportées par le vent et parfois par les eaux de ruissellement. Elles iront germer un peu plus loin, voire très loin si le vent les emporte à haute altitude, gage de la pérennité de l'espèce. Si les spores, à n chromosomes, sont produites sans fécondation ,...

• Nouvelles lettres d'un voyageur Parmi ces fantaisies du commencement du dernier

  VII. A MADAME ERNEST PÉRIGOIS[18] Deux amoureux sont là guettant la fleur charmante: Le papillon superbe et la bête rampante; L'une qui souille tout dans son embrassement, L'autre qui du pollen s'enivre follement. Femmes, talents, beautés, contemplez votre image; Toujours un ennemi s'abreuve de vos fleurs, Soit qu'il dévore, abject, la tige et le feuillage, Soit qu'il pille, imprudent, le parfum de vos coeurs! Nohant, 30 mai 1856 [Note 18: Écrit sur son album, au-dessous d'un des...

• Biodiversity.

  a common molecule, ribonucleic acid (RNA), and most also have deoxyribonucleic acid (DNA). These molecules direct the production of proteins—molecules responsiblefor the structure and function of virtually all living cells. This is the evolutionary chain of life. All species are descended from a single common ancestor. From that ancient single-celled microbe, all inherited RNA. As time goesby, species diverge and develop their own peculiar attributes, thus making their own contribution to biodiv...

• Biodiversity - biology.

  a common molecule, ribonucleic acid (RNA), and most also have deoxyribonucleic acid (DNA). These molecules direct the production of proteins—molecules responsiblefor the structure and function of virtually all living cells. This is the evolutionary chain of life. All species are descended from a single common ancestor. From that ancient single-celled microbe, all inherited RNA. As time goesby, species diverge and develop their own peculiar attributes, thus making their own contribution to biodiv...

• Sewage Disposal.

  greater load on the piping system and the treatment plant. The amount of storm-water drainage to be carried away depends on the amount of rainfall as well as on the runoff or yield of the watershed ( see Drainage). A typical metropolitan area discharges a volume of wastewater equal to about 60 to 80 percent of its total daily water requirements, the rest being used for washingcars and watering lawns, and for manufacturing processes such as food canning and bottling. B Composition The composi...

• Dinosaur - biology.

  The behavior of dinosaurs was governed by their metabolism and by their central nervous system. The dinosaurs’ metabolism—the internal activities that supply thebody’s energy needs—affected their activity level. It is unclear whether dinosaurs were purely endothermic (warm-blooded), like modern mammals, or ectothermic (cold-blooded), like modern reptiles. Endotherms regulate their body temperature internally by means of their metabolism, rather than by using the temperature oftheir surroundin...

• domestication.

  ces plantes près des lieux de séjour des groupes paléolithiques. Non consommées ou perdues, les semences ont contribué à la modification de la répartition et de la qualité des espèces. L'autofécondation a été favorisée par la récolte sur un nombre limité d'individus. Simultanément, une sélection inconsciente a été opérée, l'homme récoltant ce qui lui paraissait le meilleur ou le plus productif. Dès le néolithique s'est organisée autour des habitations une culture volontaire des espèces consommée...

• Environment.

  escape into space of the infrared energy radiated back out by Earth. This process is referred to as the greenhouse effect. These gases, primarily carbon dioxide,methane, nitrous oxide, and water vapor, insulate Earth’s surface, helping to maintain warm temperatures. Without these gases, Earth would be a frozen planet with anaverage temperature of about -18°C (about 0°F) instead of a comfortable 15°C (59°F). If the concentration of these gases rises, they trap more heat within theatmosphere, caus...

• Diving (underwater).

  compensator (or control) device (BCD or BC), which the diver wears as a vest. By adding air to the BCD, the diver becomes more buoyant and rises. By releasing air,the diver becomes less buoyant and sinks. With minor adjustments of air, the diver can achieve neutral buoyancy. A third hose attaches to pressure gauges that diversuse to monitor how much air remains in the tank. A fourth hose attaches to a backup breathing device called an alternate air source, or octopus. Divers also wear a belt w...

• Michigan - geography.

  The interior location of Michigan in the northern part of North America results in a continental climate, characterized by four definite seasons with moist, mild to hotsummers and snowy, cold winters. Winds off of Lakes Michigan and Superior in winter create heavy snow accumulations in nearby areas. The tempering effects of LakeMichigan account for the presence of the state’s famous fruit-growing belt along the lake’s shore. Since the water is colder than the land in spring, the westerly windspa...

• Michigan - USA History.

  The interior location of Michigan in the northern part of North America results in a continental climate, characterized by four definite seasons with moist, mild to hotsummers and snowy, cold winters. Winds off of Lakes Michigan and Superior in winter create heavy snow accumulations in nearby areas. The tempering effects of LakeMichigan account for the presence of the state’s famous fruit-growing belt along the lake’s shore. Since the water is colder than the land in spring, the westerly windspa...

• Washington (state) - geography.

  The crest of the Cascade Range divides Washington into two distinct climatic regions. The area west of the Cascades, which is exposed throughout the year to rain-bearing winds from the Pacific Ocean, has a temperate marine type of climate that is characterized by mild wet winters and cool summers. The Cascades prevent themoist air blowing in from the Pacific from reaching eastern Washington. The Rocky Mountains on the eastern border also represent a climatic barrier. As a result, thesevere winte...

• Washington (state) - USA History.

  The crest of the Cascade Range divides Washington into two distinct climatic regions. The area west of the Cascades, which is exposed throughout the year to rain-bearing winds from the Pacific Ocean, has a temperate marine type of climate that is characterized by mild wet winters and cool summers. The Cascades prevent themoist air blowing in from the Pacific from reaching eastern Washington. The Rocky Mountains on the eastern border also represent a climatic barrier. As a result, thesevere winte...

• Dinosaurio - ciencias de la naturaleza.

  © Microsoft Corporation. Reservados todos los derechos. Los antepasados de los dinosaurios fueron un grupo de arcosaurios primitivos llamados tecodontos que aparecieron a principios del periodo triásico. Algunos arcosaurios seconvirtieron en verdaderos cocodrilos y otros en pterosaurios, reptiles voladores con alas compuestas de membranas finas de piel apoyadas sobre un solo dedo en forma depalo. También otros arcosaurios adoptaron la postura bípeda (sostenidos sobre dos patas) y ciertas especie...

• Les fougères

  cycle biologique des fougères sont de petites bouteilles dont la partie renflée contient une cellule reproductrice femelle, ou oosphère. Le col, dirigé vers le bas, est bouché par une sorte de gel. Au niveau des poils rhizoïdes sont disséminés les organes mâles, ou anthéridies, petites capsules contenant les cellules reproductrices mâles ou anthérozoïdes. Elles sont munies, comme les spermatozoïdes des animaux , d'un flagelle leur permettant de se...

• Arkansas - geography.

  temperature rises to the upper 30°s C (lower 100°s F). C2 Precipitation Arkansas receives about 1,000 to 1,300 mm (about 40 to 50 in) of precipitation a year, and some areas receive even more. Most of the rain comes during winter andspring and at times is so heavy as to cause flooding. Snow is rare in the south but amounts to more than 250 mm (10 in) a year in the mountains. C3 Growing Season Arkansas has a long growing season. It averages 211 days for the state as a whole and ranges from 241...

• Arkansas - USA History.

  temperature rises to the upper 30°s C (lower 100°s F). C2 Precipitation Arkansas receives about 1,000 to 1,300 mm (about 40 to 50 in) of precipitation a year, and some areas receive even more. Most of the rain comes during winter andspring and at times is so heavy as to cause flooding. Snow is rare in the south but amounts to more than 250 mm (10 in) a year in the mountains. C3 Growing Season Arkansas has a long growing season. It averages 211 days for the state as a whole and ranges from 241...

• Antarctica - Geography.

  The maximum area of sea ice surrounding Antarctica each winter varies from year to year. A marked decline during the 1970s appears to have reversed in more recentdecades, except in the Antarctic Peninsula area. This area has lost almost 40 percent of its sea ice since the start of the 1980s. Sea ice is important to marine life. Krillfeed on algae that live under the sea ice and are released when the ice melts in spring and summer. In turn, many marine animals feed on krill. Emperor penguinsbreed...

• Nunavut - Canadian History.

  The Arctic Lands is a complex geological area that is centered on the Arctic Ocean. It includes coastal plains, plateaus, and mountains. Coastal plains and plateaus arefound in the western Northwest Territories section of the Arctic Lands, such as on Victoria Island, which is mostly a large, flat plateau. In striking contrast to theserelatively gentle landscapes, the eastern Nunavut section of the Arctic Lands is dominated by a jagged chain of ice-covered mountains. The mountains on EllesmereIsl...

• Camping.

  Commercial campgrounds serve as campsites for RV and car campers on the outskirts of national and state parks and along highways throughout North America.Owners of commercial campgrounds charge campers on a daily or weekly basis, and provide campsites equipped with hookups for electricity and water. They may alsoprovide such amenities as showers, laundry facilities, or a swimming pool. Many commercial campgrounds belong to a club or network that allows its members toreserve campsites in advance....

• Newfoundland and Labrador - Geography.

  Precipitation averages about 1,120 mm (about 44 in) yearly in Newfoundland. In Labrador precipitation varies from about 1,020 mm (about 40 in) in the southeast toabout 510 mm (about 20 in) in the extreme north. Heavy winter snowfalls are common, especially in Newfoundland. D Plant Life About one-third of Newfoundland is forested, and most of the rest of the island is made up of barren areas of reindeer moss and lichens. The forests consist almostentirely of conifers. The most important species...

• Newfoundland and Labrador - Canadian History.

  Precipitation averages about 1,120 mm (about 44 in) yearly in Newfoundland. In Labrador precipitation varies from about 1,020 mm (about 40 in) in the southeast toabout 510 mm (about 20 in) in the extreme north. Heavy winter snowfalls are common, especially in Newfoundland. D Plant Life About one-third of Newfoundland is forested, and most of the rest of the island is made up of barren areas of reindeer moss and lichens. The forests consist almostentirely of conifers. The most important species...

• Alberta - Geography.

  C Climate Except for the mountain areas, summers throughout the province are quite warm. Winters are long and extremely cold. In July, average daily temperatures range fromabout 16°C (about 60°F) along the northern boundary to about 21°C (about 70°F) in the south. In the extreme southeastern section of the province, temperatures of43°C (110°F) have been recorded. In January, average daily temperatures range from about -14°C (about 6°F) at Grande Prairie to about -9°C (about 16°F) atCalgary. Tem...

• Alberta - Canadian History.

  C Climate Except for the mountain areas, summers throughout the province are quite warm. Winters are long and extremely cold. In July, average daily temperatures range fromabout 16°C (about 60°F) along the northern boundary to about 21°C (about 70°F) in the south. In the extreme southeastern section of the province, temperatures of43°C (110°F) have been recorded. In January, average daily temperatures range from about -14°C (about 6°F) at Grande Prairie to about -9°C (about 16°F) atCalgary. Tem...

• photosynthèse.

  Complétez votre recherche en consultant : Les corrélats arbres - Physiologie - Respiration et photosynthèse ATP (adénosine triphosphate) autotrophie carbone chlorophylle chloroplaste écosystèmes - L'organisation fonctionnelle des écosystèmes écosystèmes - Le flux de l'énergie dans les écosystèmes énergie - Les différentes formes de l'énergie ferrédoxine feuille océanographie - L'océanographie biologique plantes - Le fonctionnement de la plante - Introduction plante...

• BIOLOGIE CELLULAIRE INTRODUCTION La recherche d'un plan unitaire d'organisation du monde des vivants et la tendance à l'unification des sciences de la vie furent synthétisées par l'élaboration de la théorie cellulaire, entre 1830 et 1850.

  2 croître, de se multiplier et de se modifier, et que commença à s'affirmer l'image de l'organisme comme société de cellules. Les premières contributions importantes concernant les cellules animales furent apportées par Jan E. Purkinje (1787-1869). Dès 1832, lorsqu'il commença à observer au microscope les tissus animaux, ce physiologiste tchèque releva la présence de cellules et établit une analogie étroite entre les structures élémentaires des plantes et celles des animaux. À partir de ces don...

• Republic of Indonesia - country.

  Mahakam in East Kalimantan and the Martapura and Barito in South Kalimantan. Most of these rivers originate in the island’s central massif (mountain mass) and meander through extensive swamps as they approach the coast. Settlements such as Samarinda and Banjarmasin cluster along the rivers, which serve ascommunication routes into the interior. The largest rivers on Sumatra drain from west to east into the Strait of Malacca. In the north, the Asahan River once linked trade between the Batak peo...

• Texas - geography.

  D Climate Eastern Texas has a humid subtropical climate, while a semiarid low latitude climate prevails in central areas, and an arid low latitude climate in the extreme west. Alongthe coast the climate is much milder, with fewer extremes in temperatures. Hurricanes sometimes hit the coastal areas of Texas from late July through September, andtornadoes are common in north-central Texas in April and May. D1 Temperature Summers are hot throughout the state, and temperatures exceeding 35°C (95°F)...