Write the difference between chasmogamous and cleistogamous flowers.
Hint: Chasmogamous and cleistogamous refer to the positioning of reproductive organs in flowers. These flowers can perform self-fertilization when cross-pollination isn’t feasible. The two main types of flowers are chasmogamous and cleistogamous.
Complete Answer:
A flower is the reproductive part of a plant, housing both male and female gametophytes. The male reproductive organ, called the androecium, is composed of a circle of stamens, while the female reproductive organ is known as the gynoecium. Fertilization happens following pollination. In some flowers, self-fertilization occurs, whereas others undergo cross-fertilization.
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Chasmogamous flower |
Cleistogamous flower |
| 1. Chasmogamous flowers have exposed anthers and stigma. | 1. Cleistogamous flowers stay closed, with the anthers and stigma positioned close together. |
| 2. Chasmogamous flowers generally rely on cross-pollination, requiring pollinators to transfer pollen. | 2. Cleistogamous flowers are limited to self-pollination. |
| 3. To encourage cross-pollination, chasmogamous flowers often feature vibrant petals and nectar guides to attract and reward pollinators. | 3. Cleistogamous flowers don’t need pollinators or showy parts like colorful petals or nectaries. |
| 4. Seeds from chasmogamous flowers are genetically diverse. | 4. Without pollinators, cleistogamous flowers still ensure seed production. |
Note: Complete autogamy is rare in typical open flowers with exposed anthers and stigma. For autogamy to occur, the release of pollen and the stigma’s receptivity must be synchronized, and both anthers and stigma should be positioned close together to enable self-pollination.