Angiosperms Have Covered Seeds

Angiosperms Have Covered Seeds

     Angiosperms (seed plants that bear seeds protected by a fruit) are more diverse than the other types of plants. Their success may be associated with climatic changes in the Cenozoic era.
     In a flower, the microsporangia develop within the anther portion of a stamen, and the megasporangia develop within ovules located in the ovary of the pistil. Pollination brings the mature microgametophyte (pollen grain) to the pistil, and the pollen tube brings the sperm to the ovule within the ovary. Angiosperms exhibit double fertilization: one sperm fertilizes the egg, and the other unites with the polar nuclei to form the endosperm, which is food for the
embryo. The ovule develops into the seed, and the ovary becomes the fruit.    
   Angiosperms have complex vascular tissue and are found in various habitats. Their reproductive organs are found in flowers. Animal pollination increases the chance of appropriate fertilization, and fruit production often assists the dispersal of seeds.