An angiosperm has flowers that open to be pollinated. The male part of the plant, called the stamen, contains pollen that is transferred to the female part of the plant, called the pistil, which contains eggs that are fertilized by the sperm inside the pollen. These eggs form many seeds within a fleshy fruit. The fruit drops to the ground when mature, and then the cycle starts over.Continue Reading
Many angiosperms have separate plants containing male and female parts; the pollen in these plants is carried by insects or other animals to help with fertilization. Others are self-pollinating, containing both the male and female structures on the same plant.
Pollen contains microspores that are the male cells found in the stamen. The female cells that are found in the pistil and divide to become the egg are called megaspores. In some plants, these are the only parts of the flower. Other plants contain structures called sepals and petals that attract insects and birds and protect the seed.
In contrast to gymnosperms, such as pine and ginkgo trees, the seeds of angiosperms are enclosed within a fruit. Angiosperms replaced gymnosperms as the most dominant plant approximately 60 to 100 million years ago.Learn more about Botany