Final answer:
The ovary of the flower becomes the fruit after successful pollination and fertilization, facilitating seed dispersal and species propagation.
Step-by-step explanation:
The part of the flower that traditionally becomes the fruit is the ovary. When pollination occurs and fertilization is successful, the walls of the ovary thicken and develop into a fruit. This fruit contains the seeds, ensuring the dispersal and continuation of the plant species. The process begins when pollen from the anther is transferred to the stigma; following this, a pollen tube grows down the style into the ovary where fertilization occurs.
The other floral structures, such as the stamen, which includes the anther and filament, and the brightly colored petals, serve different purposes related to the reproduction of the plant but do not form the fruit.