What is the term for the first leaf produced by an embryo in seed plants?

The term for the first leaf produced by an embryo in seed plants is "cotyledon." Cotyledons are crucial because they serve as the initial source of nourishment for the developing plant seedling, providing energy and nutrients until the true leaves form and the plant can begin photosynthesis. Cotyledons are distinct from true leaves, which appear later in the plant's development and typically have a different shape and function. Understanding the role of cotyledons is essential in botany, as they are a fundamental part of seed biology and plant development.