Pollen grain formation

Référence de la vidéo 11936060
Pollen grain formation. Animation of successive steps showing how pollen grains (the germinal cells of plants) are formed. The animation starts with a flower (red, lower left), followed by a close-up of a stamen consisting of anthers (brown) on a filament (blue). The anthers consist of pollen sacs. The next stage of the animation shows a cross-section through an anther to show the pollen sacs (four shown). The wall of each pollen sac contains the tapetum (red). This is where the cells that will form pollen grains undergo meiosis (glowing areas) in a process called microsporogenesis. At upper right, the division of a microsporocyte (orange, genetic material in nucleus) forms first a dyad, then a triad. The process continues (lower right) with the formation of distinct single-celled haploid microspores. The final stage is the formation of a pollen grain (lower centre). When this pollen grain comes into contact with the stigma of a flower, the pollen grain germinates and produces a pollen tube (final diagram) down which the sperm nuclei pass to fertilise the female parts of the flower. For this animation without labels, see K004/0379.
Licence : Droits gérés
Crédit : Science Photo Library / Biocosmos / Francis Leroy & Victor Velut
Model Release : Non requis
Durée : 46 Secondes
Aspect ratio : 16/9
Restrictions : -

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