Fertilization
3 Minutes
Fertilization in plants for kids: learn how gametes fuse, seeds and fruits form, and post-fertilization changes happen. An English science lesson.
- How pollen tubes form and male and female gametes make a zygote
- How ovules turn into seeds and ovaries turn into fruits
- Post-fertilization changes, like calyx remaining on tomatoes
What this lesson teaches
Fertilization is the process where a male gamete fuses with a female gamete inside a flower to form a zygote (karuvurutal). It is the key step after pollination that allows a flower to develop into a complete fruit containing seeds.
The path of the pollen grain
For a flower to turn into a fruit, two main processes must happen: pollination and fertilization. Pollination occurs when pollen grains from the male reproductive part reach the stigma of the female reproductive part through natural or artificial pollination. Once the pollen grain lands on the stigma, a pollen tube forms between the stigma and the ovary like a road. The male gamete inside the pollen grain travels down this road all the way to the ovary.
Gamete fusion and zygote formation
- The male gamete inside the pollen grain travels down through the pollen tube into the ovary.
- Inside the ovary, the male gamete reaches the ovule where the female gamete is present.
- The male gamete meets and fuses directly with the female gamete.
- This fusion produces a zygote, which marks the completion of the fertilization process.
Post-fertilization changes
When a flower turns into a fruit, it undergoes several changes called post-fertilization changes, similar to the visible changes in a mother's body during pregnancy. The corolla falls off after fertilization takes place. Next, the male parts, including the anther and the stamen, also fall off. In some fruits, such as tomatoes, green chilies, and strawberries, the calyx stays attached and grows with the fruit, appearing as a green cap-like part on top.
Development of fruits and seeds
- The ovule inside the ovary transforms into a seed after fertilization.
- The ovary surrounding the ovule turns into the fleshy part, becoming a complete fruit like an apple, orange, pineapple, or custard apple.
- Any fruit or vegetable containing seeds is the result of sexual reproduction through pollination and fertilization.
- Plant structures without seeds, such as a potato, are formed through asexual reproduction.