Question

Draw a diagram that illustrates the life cycle of flowering plants. Why don’t flowering plants require a source of outside water for pollination?

Answer 1

The sporophytic plant bears flowers that contain both male and female reproductive organs. The male gametophyte develops within the pollen grain and produces sperm (male gametes), whereas the female gametophyte (embryo sac) develops inside the ovule within the ovary and produces the egg cell. The microspore mother cells and megaspore mother cells undergo meiosis to form haploid microspores and megaspores, which then develop into male and female gametophytes, respectively. Pollination takes place by wind or insect agents, transferring pollen grains to the stigma of a flower, where double fertilization occurs. During this process, one male gamete fuses with the egg to form a zygote, and the other fuses with the central cell to form the endosperm nucleus, which nourishes the developing embryo. The zygote develops into an embryo inside the seed, which originates from the ovule. The ovary develops into a fruit enclosing the seed, helping in seed protection and dispersal. After germination, the seed gives rise to a new sporophytic plant, completing the life cycle of a flowering plant.

Flowering plants do not require an outside source of water for pollination because angiosperms rely on wind, insects, or other animals to transfer pollen from the anther to the stigma.

Moreover, male gametes are carried within the pollen tube directly to the egg cell, so fertilization occurs internally, without the need for motile sperm or water as a medium.