List down and explain the phases of Germination
The process of germination is the beginning growth stage of a seed. It involves several phases, each crucial for the successful development of a plant. The following are the phases of germination:
1. Imbibition: In this phase, the dry seed absorbs water from the soil through its seed coat. The embryo inside the seed starts to hydrate, which activates various enzymes and biochemical processes necessary for growth.
2. Activation: Once imbibition occurs, the dormant embryo inside the seed is triggered to begin metabolic activities. Hormones, such as gibberellin, are produced, which stimulate the embryo to break through the seed coat.
3. Respiration: During this phase, the embryo begins to respire, converting stored energy in the form of carbohydrates into ATP (Adenosine Triphosphate) for growth and development. Cellular respiration provides the energy required for cell division and elongation.
4. Radicle emergence: The radicle is the first part of the seedling to emerge from the seed. It starts as a tiny root that pushes through the seed coat and anchors the seedling into the soil. The radicle enables the uptake of water and nutrients from the soil.
5. Shoot development: Once the radicle is established, the shoot system starts to develop. The shoot emerges from the cotyledons, which contain stored nutrients, and transforms into the stem and leaves. The leaves perform photosynthesis, producing energy for the growing seedling.
6. Seedling growth: As the shoot system develops, the seedling undergoes rapid growth. The stem elongates, and the leaves expand, allowing the seedling to reach towards sunlight. The roots continue to grow, enabling the absorption of water and minerals from the soil.
7. Establishment: During this final phase, the seedling becomes established as a young plant. Its roots penetrate deeper into the soil, anchoring it firmly. The shoots continue to grow, strengthening and branching out. The seedling begins to take on the characteristics of its mature plant form.
These phases collectively ensure a successful transition from a dormant seed to a fully functioning plant. Each phase is vital and requires appropriate environmental conditions, such as suitable temperature, moisture, and oxygen levels, to optimize germination and support healthy plant growth.