photo.jpg

## Fertilization In Flowering Plants **Characteristics of Water-Pollinated Flowers** * Flowers are small and light so that they can easily float on water. * Male and female flowers are borne on separate plants. * Pollen grains are produced in large numbers. **Fertilization** (Fusion of male and f...

## Fertilization In Flowering Plants **Characteristics of Water-Pollinated Flowers** * Flowers are small and light so that they can easily float on water. * Male and female flowers are borne on separate plants. * Pollen grains are produced in large numbers. **Fertilization** (Fusion of male and female sex cells): After reaching the stigma of the flower of the same kind of plant, the pollen grain absorbs moisture from the stigma's surface and begins to grow a tube. This tube is called the pollen tube. The pollen tube lengthens through the style and enters the ovule in ovary. There, it releases the male gametes (or germ cells) which fuse with the female egg cell in the ovule to produce a zygote. Fertilization is the fusion of the male cell with the female cell to produce a zygote. The ovule containing the fertilized cell develops into a seed. The covering of the ovule gives rise to the seed coat and the ovary containing the seeds develops into a fruit. The ovary remains attached to the stalk of the flower and grows into a fruit. The ovules inside the ovary develop into seeds. Other parts, like the sepals and petals fall off. **Fig. 2.13 Pollen tube entering the ovule** **Fig. 2.14 Flow chart showing fertilization** * **1. Pollination** * **2. Germination of pollen tube** * **3. Penetration of the ovule** **Artificial Pollination** Artificial pollination means transfer of pollen grain manually. Now-a-days artificial pollination is practised by plant breeders for developing new varieties of plants with desired characteristics, like one variety may be high yielding and the other may be disease resistant. **Objective Type Questions:** **Fill in the blanks by choosing the appropriate word:** * (a) A flower that bears only one type of sex organs is called **unisexual**. * (b) A flower bearing both male and female reproductive organs is called **bisexual**. * (c) Transfer of pollen grains by wind is called **wind pollination**. * (d) Fusion of male and female gametes is called **fertilization**. * (e) The ovule after fertilization develops into a **seed**. * (f) The ovary after fertilization develops into a **fruit**. **Name the part of flower that:** * (a) develops into a fruit: **Ovary** * (c) produces pollen grains: **Anther** * (e) contains the ovule: **Ovary**