Class 11 Gymnosperm

The gymnosperms have ovules which are not enclosed by any ovary wall. The seeds remain exposed after fertilization and so these plants are called naked-seeded plants. The gymnosperms produce microspores and megaspores in microsporangia and megasporangia respectively. Microsporangia are borne on microsporophylls while megasporangia are borne on megasporophyll. These sporophylls are arranged spirally on axis to form male and female cones. The pollen grain germinates and pollen tube releases the male gamete into the ovule, where it fuses with the egg cell in archigonia. After fertilization, the zygote develops into embryo and the ovules into seeds. 

Note: The above notes in the image(s) are taken from a personal notebook which was initially not intended to be shared online. Please excuse the rough handwriting and spelling errors, if any.