Which part of the seed emerges and grows into the soil?

The radicle is the part of the seed that emerges first and grows down into the soil during germination. It is the embryonic root that anchors the plant and begins the process of nutrient and water absorption from the soil. This growth direction establishes the foundational root system that supports the plant as it grows.

In the context of seed structure, the radicle's role is crucial because it is the first sign of life after a seed has been dormant. As the radicle grows, it will eventually develop into the primary root of the plant, facilitating further growth and stability.

The other parts of the seed serve different functions. The embryo consists of the entire young plant, including the radicle, but it is not specific to the root component alone. The endosperm provides the necessary nutrients for the developing seedling, but it does not grow into the soil. Cotyledons, often referred to as seed leaves, serve as a food source as well and may photosynthesize if they are capable, but they do not root themselves in the soil; instead, they usually emerge above ground. Hence, it is the radicle that specifically fulfills the role of growth into the soil.