4 résultats pour "endosperme"
- endosperme, n.
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Fruit - biology.
from a flower with several pistils. The ovary may have a single compartment, or carpel, which houses the ovule or ovules. Or the ovary may consist of two or morecarpels, each of which may contain one or more ovules. A drupe develops from an ovary with a single carpel and is characterized by an edible exocarp and mesocarp and an inedible, hard endocarp, or pit that encloses asingle seed. Cherries, peaches, apricots, and plums are examples of drupes. Almonds also are classified as drupes, but in a...
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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...
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Samen - Biologie.
Bevor ein Samen auszukeimen beginnt, muss er eine Reihe von Hürden meistern, die meist ökologische Ursachen haben. Die Samen der Herbstblüher, wie Astern oderChrysanthemen, könnten theoretisch durchaus noch in einem milden Herbst auskeimen, hätten dann aber den harten Winter vor sich. Deshalb benötigen viele Samen einklimatisches Signal, um keimbereit zu sein. Dieses Signal sind Temperaturen um den Gefrierpunkt im Winter. Solange es so kalt ist, keimen die Samen aus physiologischenGründen nicht...