Reproduction in Plants: Sexual MCQs Quiz | Class 10

Understanding Reproduction in Plants: Sexual Mode

Sexual reproduction in plants is a fascinating biological process that ensures the continuity of plant species. It involves the fusion of male and female gametes, typically found within flowers, leading to the formation of seeds and fruits.

Key Components of a Flower and Their Roles:

Flowers are the reproductive organs of angiosperms (flowering plants). They consist of several parts, each with a specific function:

• Sepals: Usually green, leaf-like structures that protect the bud before it opens.
• Petals: Often brightly colored and scented to attract pollinators like insects and birds.
• Stamen (Male Part): Consists of two main parts:
  • Anther: Produces and stores pollen grains (which contain male gametes).
  • Filament: A stalk that supports the anther.
• Pistil/Carpel (Female Part): Consists of three main parts:
  • Stigma: The sticky tip that receives pollen during pollination.
  • Style: A tube-like structure connecting the stigma to the ovary.
  • Ovary: Contains ovules, which house the female gametes (egg cells).

Pollination: The Transfer of Pollen

Pollination is the process by which pollen grains are transferred from the anther to the stigma. It is a crucial step before fertilization can occur.

• Self-pollination: Occurs when pollen is transferred from the anther to the stigma of the same flower or another flower on the same plant.
• Cross-pollination: Occurs when pollen is transferred from the anther of one flower to the stigma of a flower on a different plant of the same species.

Agents of Pollination: These are the carriers that help in the transfer of pollen. Common agents include wind, water, insects (like bees, butterflies), birds, and other animals.

Fertilization: Fusion of Gametes

After a pollen grain lands on a compatible stigma, it germinates and grows a pollen tube down through the style to reach the ovule in the ovary. The male gametes from the pollen grain then fuse with the female gamete (egg cell) inside the ovule. This fusion of male and female gametes is called fertilization.

Fertilization results in the formation of a zygote, which then develops into an embryo.

Post-Fertilization Changes: Seed and Fruit Formation

Following fertilization, significant changes occur in the flower:

The fruit protects the developing seeds and aids in their dispersal, ensuring the continuation of the plant life cycle.

Quick Revision Checklist:

• Sexual Reproduction: Fusion of gametes (male and female).
• Flower: Reproductive organ of angiosperms.
• Stamen: Male part (Anther produces pollen).
• Pistil/Carpel: Female part (Stigma receives pollen, Ovary contains ovules).
• Pollination: Transfer of pollen (self or cross).
• Fertilization: Fusion of male and female gametes (forms zygote).
• Ovary → Fruit; Ovule → Seed.

Practice Questions:

1. Name the male reproductive part of a flower.
2. What is the function of the stigma?
3. Differentiate between self-pollination and cross-pollination.
4. What happens to the ovule after fertilization?
5. Give two examples of pollinating agents.