germination of seed
Germination is the process by which a seed begins to grow and develop into a new plant. It occurs when the conditions are right for the seed to start utilizing its stored resources and initiate the growth process. This usually happens when the seed is exposed to water, oxygen, and suitable temperature.
Here is a step-by-step explanation of the germination process:
1. Water absorption: When a seed comes in contact with water, it absorbs the moisture through its seed coat. This triggers the activation of enzymes within the seed.
2. Activation of enzymes: The absorption of water activates enzymes that were dormant within the seed. These enzymes help in breaking down complex molecules stored in the seed, such as starches and proteins, into simpler forms that the seed can use for growth.
3. Cell division: As the stored nutrients are broken down, the seed begins to undergo rapid cell division. This leads to the growth of the embryonic root, called the radicle, which will anchor the young plant into the soil.
4. Emergence of the radicle: The radicle grows downward, usually in the opposite direction of gravity, to establish the plant's roots. This allows the plant to absorb water and minerals from the soil.
5. Shoot growth: As the radicle continues to grow and establish the root system, the embryonic shoot, known as the plumule, starts to develop. The plumule will eventually emerge from the soil and grow into the above-ground part of the plant.
6. Photosynthesis: As the plumule emerges from the soil and exposes the young leaves to light, the process of photosynthesis begins. Photosynthesis is the process by which plants convert sunlight, water, and carbon dioxide into usable energy in the form of sugars.
7. Development of true leaves: The initial leaves that emerge from the plumule are called cotyledons or seed leaves, which have nutrients stored in them. As the plant continues to grow, it produces true leaves that are capable of performing photosynthesis and provide the plant with energy.
Throughout the process of germination, the seedling requires suitable temperature and proper oxygen availability. Different plant species have different requirements for successful germination.