Final answer:
The sporogenous cells of angiosperms develop directly into microsporocytes, which then form microspores and ultimately mature into pollen grains.
Step-by-step explanation:
The sporogenous cells of angiosperms develop directly into microsporocytes. These microsporocytes, which are also known as microspore mother cells, undergo meiosis to produce four haploid microspores. Each microspore then undergoes a process to eventually form a pollen grain. Mature pollen grains contain a generative cell and a tube cell. During pollination, it is these pollen grains that are transferred to the stigma of a flower, leading to fertilization.