Sexual Reproduction in Flowering Plants
Sexual reproduction in flowering plants involves the formation and fusion of male and female gametes, producing seeds that can grow into new plants.
Parts of a Flower
Stamen (Male Part):
Anther: Produces pollen grains, which contain male gametes.
Filament: Supports the anther.
Pistil/Carpel (Female Part):
Stigma: Sticky surface that captures pollen.
Style: Tube that connects the stigma to the ovary.
Ovary: Contains ovules, which develop into seeds after fertilization.
Petals: Often colorful, attract pollinators.
Sepals: Protect the flower bud before it opens.
Steps of Sexual Reproduction
Pollination
Transfer of pollen from the anther to the stigma. Can occur through various agents like wind, water, insects, birds, or other animals.
Fertilization
After pollination, pollen grains germinate on the stigma, growing a pollen tube down the style to reach the ovule. The male gamete travels through the pollen tube and fuses with the female gamete (egg cell) in the ovule. This fusion creates a zygote, which will develop into an embryo.
Seed and Fruit Formation
The fertilized ovule develops into a seed containing the embryo and a food supply. The ovary surrounding the ovule develops into a fruit, which protects the seeds and aids in their dispersal.
Seed Dispersal
Seeds can be spread by wind, water, animals, or other methods, ensuring they grow in new locations.
Importance of Sexual Reproduction in Plants
Genetic Variation: The mixing of genetic material from two parents leads to variation in offspring, which is beneficial for adaptation and survival.
Species Survival: Enables plants to adapt to changing environments and resist diseases.
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