What is a protective shell surrounding the embryo and endosperm of a seed?

The protective shell surrounding the embryo and endosperm of a seed is known as the seed coat or testa. This outer layer serves as a protective barrier that shields the embryo and endosperm from physical damage, pathogens, and desiccation. The seed coat can vary in thickness and texture, depending on the plant species, and it plays a crucial role in seed dormancy and germination. By preventing water loss and protecting the seed’s internal tissues, the seed coat ensures that the seed can survive adverse environmental conditions until it finds a suitable environment for germination.