As a result of pollination – the transfer of pollen from anthers on the stigma of a pestle, pollen grain – a speck of dust, begins to germinate. With the participation of a vegetative cell, a pollen tube is formed along which the generative cell moves. It gives rise to two male gametes sperm. Sperm is a flagellate-free sperm that is not capable of active movement. The pollen tube moves down to the ovary and grows into the embryo sac in the area of the pollen duct. After this, the tip of the tube breaks and two sperm enters the embryo sac. Some of them merge with the egg, forming a zygote, and the other with the central nucleus, forming the triploid nucleus of the central cell. An embryo with a diploid set of chromosomes develops from a zygote, and an endosperm (nutritious seed tissue) develops from a triploid cell. From the integument of the ovum, the peel of the seed is laid, and from the walls of the ovary, the pericarp. Thus, a flower is a shortened spore-bearing shoot, which serves to form spores and gametes, for pollination and fertilization, after which fruits and seeds are formed.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.