Seeds vary in size form very small to large. The primary dispersal agent is the seed and depending upon the flower, they may be dispersed as seeds or part of the fruit. The two subclasses of Anthophyta are Dicotyledonae and Monocotyledonae. The cotyledon is the seed leaf, or one pair of leaves, of the embryo plant. The angiosperms are separated into monocots and dicots by the number of seed leaves or cotyledons.
Monocots have one cotyledon and dicots have two cotyledons.
In dicots, the leaves or cotyledons serve as a source of food for the growing plant and sometimes for photosynthesis. In monocots, the endosperm is the basic food reserve. The cotyledon absorbs food from the endosperm and transmits it to the growing part of the plant. The flower, which develops into a fruit, distinguishes angiosperms from other vascular plants. Pollination is the transfer of pollen from the pollen sacs of a male to the female site on the same or different plant.