DENDROLOGY

Detailed explanation-1: -From the anther the pollen grains are first deposited on the pistil’s surface, the stigma . There they germinate and form pollen tubes, which grow downward through the style toward the ovules . Fertilization occurs as a sperm cell in a pollen tube fuses with the egg cell of an ovule, resulting in a plant embryo .

Detailed explanation-2: -When the pollen grain germinates on the stigma it creates a burrow called the pollen tube as it travels toward the ovary. When the sperm cell from the pollen grain reaches the ovary or ovule the sperm joins with the egg. This is called fertilization. The fertilized zygote will become a tiny new plant inside the seed.

Detailed explanation-3: -Pollen tubes grew through one stigma to the base of the ovary at almost the same speed, but generally only one of the pollen tubes then turned towards the ovule and finally entered the nucellus through the micropyle.

Detailed explanation-4: -The generative cell is contained within the larger pollen tube cell. Upon germination, the tube cell forms the pollen tube through which the generative cell migrates to enter the ovary. During its transit inside the pollen tube, the generative cell divides to form two male gametes (sperm cells).