In gymnosperms, sexual reproduction takes place by the formation of male and female cones. The cones are either borne on the same plant as in Pinus or two different plants as in Cycas. The male cone contains microsporophyll, each microsporophyll bears microsporangia. They are sac-like structures that produce pollen grains or microspores. Each microspore is a male gametophyte forming a male gamete. 

The female cone contains megasporophyll, each megasporophyll bears ovules, the ovules contain the female gametophyte that gives rise to the egg cell.

In gymnosperms, pollination is by wind, i.e. Anemophily, the pollen grains are deposited in the pollen chamber of the ovule that contains archegonia.

Archegonia contains egg. The fusion of male gamete and egg takes place in the archegonia through siphonogamy to form a diploid zygote. The diploid zygote then develops into an embryo.