where does germination of a pollen grain occur
Germination Another germination event during the life cycle of gymnosperms and flowering plants is the germination of a pollen grain after pollination. Like seeds, pollen grains are severely dehydrated before being released to facilitate their dispersal from one plant to another. They consist of a protective coat containing several cells (up to 8 in gymnosperms, 2-3 in flowering plants). One of these cells is a tube cell. Once the pollen grain lands on the stigma of a receptive flower (or a female cone in gymnosperms), it takes up water and germinates. Pollen germination is facilitated by hydration on the stigma, as well as by the structure and physiology of the stigma and style.[1] Pollen can also be induced to germinate in vitro (in a petri dish or test tube).[10][11]
Pulse Pressure waves generated by the heart in systole move the arterial walls. Forward movement of blood occurs when the boundaries are pliable and compliant. These properties form enough to create a palpable pressure wave.
Marcus Álvarez
Corona Spectroscopy measurements indicate strong ionization and plasma temperature in excess of 1,000,000 kelvins,[1] much hotter than the surface of the Sun.