Final answer:
Post-fertilization changes leading to fruit formation start when the ovary thickens and develops into the fruit, enclosing the seeds. The development includes cell growth and tissue specialization, intended to protect the seeds and enhance their dispersal.
Step-by-step explanation:
Post-Fertilization Changes Leading to Fruit Formation in Plants
After pollination and fertilization occur in plants, several processes initiate leading to the formation of fruit. The fertilization process results in the formation of a diploid zygote, which subsequently develops into an embryo encased within a seed. This seed is a product of the transformed ovule. Concurrently, the ovary typically thickens and undergoes transformative changes that give rise to the fruit. Fruit development serves to protect the seed and facilitate its dispersal.
Fruit development in plants usually follows the successful fertilization of the female gametophyte in the ovary. The ovary wall thickens and starts to mature into a fruit. Different types of fruits develop depending on whether the ovary alone or other tissues of the female gametophyte, contribute to fruit formation. True fruits develop exclusively from the ovary, while accessory fruits involve additional floral parts.
Post-fertilization development also includes cell proliferation and the growth of tissues specific to the type of plant. This transformation often includes developing features that enhance seed dispersal, such as the appealing taste of the fruit which attracts animals, thereby aiding in the spreading of the seeds. Moreover, in some instances like parthenocarpy, fruits may develop without the seeds being fully formed. Such cases can arise spontaneously or through agricultural breeding programs aimed at producing seedless varieties, like in some tomatoes and watermelons. Despite these modifications, the primary functional goal of the fruit is typically the protection and dissemination of the developing seeds.