Mallow pollen. Coloured scanning electron micro- graph (SEM) of a pollen grain of Common Mallow,Malva sylvestris. The spherical pollen grain is about 108 micrometres across. The outer wall (exine) has numerous sharp spines which enables the pollen to attach to the body appendages of insects. The pollen is thus dispersed to other flowers which the insect visits. When the pollen,containing the male gametes,is transferred to the stigma of another flower,it germinates. A pollen tube grows out from the grain,down through the stigma,to the ovary. The male nuclei pass down the tube,fertilize the ovules and a seed is formed. Magnification: x300 at 6x6cm size | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Burgess, Dr. Jeremy |
Bildgröße: | 5079 px × 4326 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |