Plants and Their Functions

Photosynthesis and Transpiration

Plants play a vital role in sustaining life on Earth through photosynthesis, a process in which they convert sunlight into energy. This process occurs in the chloroplasts of plant cells, using carbon dioxide and water to produce glucose and oxygen. The released oxygen is essential for the survival of most living organisms.

In addition to photosynthesis, plants undergo transpiration, which is the process of water movement through a plant and its evaporation from aerial parts, especially leaves. This helps in cooling the plant, maintaining nutrient flow, and stabilizing water balance.

Transport of Water and Nutrients in Plants

The movement of water and nutrients within plants is facilitated by two key tissues: xylem and phloem.

• Xylem: Transports water and minerals from the roots to the leaves.
• Phloem: Distributes the sugars and nutrients produced during photosynthesis throughout the plant.

Root hairs absorb water from the soil through osmosis, and this water is pulled up through the xylem due to transpiration pull and cohesion forces.

Reproduction in Plants

Plants reproduce through two main methods: asexual reproduction and sexual reproduction.

Asexual Reproduction

In this type of reproduction, new plants grow from parts of an existing plant without the involvement of seeds. Common methods include:

• Cuttings: Growing new plants from stems or leaves.
• Grafting: Joining parts of two plants to create a new one.
• Rhizomes and Tubers: Underground stems that produce new plants.

Sexual Reproduction

Sexual reproduction in plants involves the formation of seeds through pollination and fertilization. The process includes:

1. Pollination: Transfer of pollen from the male anther to the female stigma.
2. Fertilization: Fusion of male and female gametes to form a seed.
3. Seed Germination: Growth of a new plant from the seed.

This method ensures genetic variation and adaptation in plants.