We all have seen trees full of fruits. Oranges, apples, peaches, nectarines, grapes are all plants that bear fruits. But, have you ever thought of how these plants produce fruits. In this lesson we are going to learn about how pollination and fertilization take place in flowers in order to produce fruits. At the end of the lesson you can go to Pollination and Fertilization Quiz and check your knowledge on the lesson.
Pollination is the transfer (move) of pollen grains from the anther (of the stamen) to the stigma (of the pistil).
1) Between pollen grains and stigma of the same flower.
2) Between pollen grains and stigma of different flowers of same species.
Pollen grains are very light in weight, so they can easily float in the air and move to other plants.
1. All flowers don’t have brightly coloured petals.
2. Some grasses have small, dull, off-white flowers.
3. This is because they are not pollinated by insects or other animals.
4. They use the wind to blow their pollen grains to other plants.
When it is raining, pollen grains can be washed away and brought to the stigma.
Animals like insects, birds and squirrels can transfer pollen grain to other flowers.
When insects like bees go from one flower to another, pollen grains in one flower can be stuck in their body parts and brought to the stigma of another flower.
After a flower is pollinated, each pollen grain which is on the stigma grows a tiny tube towards the ovules in the ovary. Then the male sex cells in pollen grains can reach the ovules and join female sex cells or eggs produced in ovules. This makes the female sex cells or eggs fertilize. This joining or the combination of male sex cells and female sex cells in a flower is what we call fertilization. Fertilization cannot take place without pollination.
After fertilization the petals, the stamen and the stigma fall off. The ovules become the seeds. The carpels and the ovary become the fruit.