9 résultats pour "pollini"
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Pollination - biology.
rapidly as in cross-pollination, because one plant with a beneficial gene can transmit it only to its own offspring and not to other plants. Self-pollination evolved laterthan cross-pollination, and may have developed as a survival mechanism in harsh environments where pollinators were scarce. IV POLLEN TRANSFER Unlike animals, plants are literally rooted to the spot, and so cannot move to combine sex cells from different plants; for this reason, species have evolved effectivestrategies for ac...
- Pollini, Maurizio - musicien.
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Honey Bee - biology.
B Reproduction and Development The queen controls the sex of her offspring. When an egg passes from her ovary to her oviduct, the queen determines whether the egg is fertilized with sperm from thespermatheca. A fertilized egg develops into a female honey bee, either worker or queen, and an unfertilized egg becomes a male honey bee, or drone. The queen lays the eggs that will develop into more queens in specially constructed downward-pointing, peanut-shaped cells, in which the egg adheres to the...
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Flower - biology.
insects. The sepals unfurl as the flower opens and often resemble small green leaves at the flower’s base. In some flowers, the sepals are colorful and work with thepetals to attract pollinators. E Variations in Structure Like virtually all forms in nature, flowers display many variations in their structure. Most flowers have all four whorls—pistil, stamens, petals, and sepals. Botanists callthese complete flowers. But some flowers are incomplete, meaning they lack one or more whorls. Incomplet...
- Pollini Maurizio, né en 1942 à Milan, pianiste italien.
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Définition:
BOYAU, BOYAUX, substantif masculin.
pour s' être un jour risqués à y goûter, avaient failli rendre tripes et boyaux. (ÉMILE ZOLA, L'Assommoir, 1877, page 609 ). · Il a toujours six aunes de boyaux vides. Il a toujours faim (attesté dans la plupart des dictionnaires généraux). Mes boyaux crient (GUSTAVE FLAUBERT, La Tentation de Saint Antoine, 1849, page 324 ); la faim lui tordait toujours les boyaux (ÉMILE ZOLA, L'Assommoir, 1877, page 752 ). · Aimer quelqu'un comme ses petits boyaux. L'aimer comme soi-même. Est-ce ton oncle Pille...
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Les feuillus
châtaigne ou la noisette ... Quelquefois, l'akène porte des excroissances en forme d'ailes pour permettre une meilleure dispersion par le vent. li peut exister une seule excroissance comme pour l'orme ou le frêne , le fruit se nommant samare , ou deux comme pour l'érable , le fruit se nommant alors disamare . D 'autres fois, le fruit est charnu et on en distingue plusieurs types : la baie , fruit en général indéhiscent et contenant une graine...
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Evolution - biology.
genetic diversity to extinction. Sexual reproduction ensures that the genes in a population are rearranged in each generation, a process termed recombination. Although the combinations of genes inindividuals change with each new generation, the gene frequency, or ratio of different alleles in the entire population, remains relatively constant if no evolutionaryforces act on the population. One such force is the introduction of new genes into the genetic material of the population, or gene pool...
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Butterflies and Moths - biology.
The smallest butterflies are certain blues that have wingspans of a mere 0.7 cm (0.25 in). The largest are the female giant birdwings of Papua New Guinea, whichmeasure up to 30 cm (12 in) across. Moths range in size from tiny Microlepidoptera, several groups of small moths with wings no more than 0.16 cm (0.06 in) across, togiant silk moths, such as the atlas moth, which may exceed 30 cm (12 in) in wingspan. IV REPRODUCTION AND LIFE CYCLE Butterflies locate potential mates by sight, identifyin...