Q.Sketch and label structure of male gametophyte in angiosperm. What is Siphonogamy?

The diploid microspore mother cell (pollen mother cell) undergoes one meiotic division (meiosis I + II counted together) to yield a tetrad of four haploid microspores. Each microspore then divides mitotically once to form a two-celled pollen grain (vegetative cell + generative cell) — the first mitotic division — and in many species the generative cell divides mitotically again to give two male gametes — the second mitotic division — completing the mature male gametophyte. So overall the p …

The diploid pollen mother cell (microspore mother cell) undergoes one meiotic division (meiosis I + II, counted as a single meiotic event) to produce a tetrad of four haploid microspores. Each microspore then undergoes its first mitotic division to form a two-celled pollen grain consisting of a large vegetative cell and a small generative cell. In many angiosperms the generative cell subsequently undergoes a second mitotic division to produce two non-motile male gametes, giving the mature three-celled male gametophyte. So the complete form …