The Process of a Seed Sprouting

A seed goes through several stages to germinate into a sprout.

Seeds only sprout in the presence of the proper proportions of light, heat and moisture. While many different species of plants exist, their process of sprouting from seed, or germination, is virtually identical.

Dormancy

A seed is protected from drying out and dying by a hard outer covering called the testa. Dormancy ends and germination is triggered when water absorbs through a small hole in the testa, called a micropyle.

Embryonic Growth

Water imbibation activates an enzyme that begins processing the endosperm in the seed, nourishing the embryo. Respiration and plant cell duplication occur, causing the embryo to grow, until it becomes so large it bursts through the testa.

Sprouting

The first part of the sprouting plant to emerge from the ruptured testa is the radicle, the plant's first root, which anchors the seed in place so the embryo can absorb nutrients and water from the surrounding soil. The next part to emerge is the plumule, or the plant's first shoot, baring one or more unfolding cotyledons, or the beginnings of the plant's first leaves.

References

• The Seeds Site: Germination Of A Seed - Types Of Germination
• Washington State University - Gardening In Western Washington: Seed Germination
• The Open Door Website: Biology - Seed Germination
• TutorVista: Stages Of Seed Germination