When a particular breed of plant is ready to reproduce it releases a substance known as pollen from its anther. Various insects and other animals transfer the pollen to the stigma of the plant. The stigma's top contains a sticky substance that specializes in capturing pollen.
After the pollen grain lands on the stigma, it absorbs some of the substance and sprouts a pollen tube. The pollen tube grows downward into the stigma and places its spores directly into the bottom of the style, where the spores merge with the plant's female cells and form a zygote.
During the zygote phase, the single cell quickly begins to divide, becoming a multi-celled embryo. This form of rapid cell division is known as mitosis. The primary endosperm cell also undergoes mitotic division to form the necessary nourishment for the growing embryo.
Growth and Development
Outside of the plant, the flower's petals have withered and shriveled away, allowing more nutrients to be given to the developing seeds. As the seeds grow, so does the ovary. In most plants, the ovary is the part of the plant that appears as its fruit. While the seeds develop, they are attached directly to the ovary that is giving the seed the nutrients to grow. If a seed is disconnected from the ovary before maturation, it will die.
Withering and Dispersal
After the seeds are fully developed, the plant will prepare for dispersal. Dispersal can occur in two different ways; first the fruit is picked by an animal and eaten, dispersing the seeds both while the fruit is eaten and in the animal's droppings. The second possibility is that the fruit will wither, open and release the seeds directly from the tree to the ground. Some plants that specialize in this type of dispersal even have measures to assist the seeds in traveling greater distances, such as thorns or an aerodynamic shape.