Mystery of Osmunda japonica pollen germination

(1) After a flower is pollinated and fertilized, the anthers, sepals and other structures gradually wither, and only the ovary continues to develop, eventually forming a fruit. In the figure, ① stigma, ④ style and ⑤ ovary constitute pistil, indicating that the ovule is ⑤.

(2) The process that pollen comes out of ② anther and falls on stigma is called pollination. When pollen is stimulated by mucus on the stigma, it germinates into a pollen tube, and the process of sperm in the pollen tube combining with the egg cells in ⑥ to form a fertilized egg is called fertilization.

/& gt； (3) After fertilization, the fertilized egg develops into an embryo, the fertilized polar nucleus develops into an endosperm, (6) the ovule develops into a seed, and the ovary wall develops into a pericarp. The edible part of peach belongs to the peel and develops from the ovary wall.

(4) Insect-borne flowers are characterized by large and bright flowers with directional odor or sweet nectar, aiming at attracting insects to pollinate them. Peach tree is an insect-borne flower. There are bees in the peach garden, which can not only collect honey, but also bring the pollen attached to the body to the stigma of another flower, which plays a key role in pollen transmission. Through bee pollination, the yield of peach trees can be greatly improved. ⑥;

(2) fertilization;

(3) ovary wall;

(4) Pollen dispersal.