AP BIOLOGY

Detailed explanation-1: -During the process of fertilization, pollen lands on the stigma, a tube grows down the style and enters the ovary. Male reproductive cells travel down the tube and join with the ovule, fertilizing it. The fertilized ovule becomes the seed, and the ovary becomes the fruit.

Detailed explanation-2: -Pollen-tube pathway During the pollination process of higher plants, after the pollen germinates on the stigmatic surface, a pollen tube is formed from the pollen and extends down the style into the ovule; nuclei from the pollen travels through the pollen tube to fertilize the ovule.

Detailed explanation-3: -Within the pollen tube, the reproductive nucleus divides into two sperm nuclei. When the pollen tube reaches the ovule’s micropyle, it releases the two sperm nuclei into the ovule. Double fertilization joins sperm nuclei with egg to form the zygote, and with 2 polar nuclei to form endosperm.

Detailed explanation-4: -After the pollen grain lands on the stigma, a pollen tube develops down through the style to the ovary. The pollen grain travels along the pollen tube and fertilizes the nucleus in the ovule. The fertilized ovule develops into a seed.