In botany, a plant embryo is part of a seed, consisting of precursor tissues for the leaves, stem, and root, as well as one or more cotyledons. It is the earliest form of a plants roots, stem, and leaves, and is contained within a seed or bud. Embryogenesis is the process that occurs after the fertilization of an ovule to produce a fully developed plant embryo. Embryogenesis occurs naturally as a result of single or double fertilization of the ovule, giving rise to two distinct structures: the plant embryo and the endosperm, which go on to develop into a seed. The zygote goes through various cellular differentiations and divisions to produce a mature embryo. The embryo develops after a fertilized adult plant flowers and is generally contained within a seed or bud. The parent plant protects the embryo by forming a container around it, which is filled with endosperm - food that the embryo can use during the early stages of germination. When the embryo detects an adequate amount of water, oxygen, and other minerals in its environment, it begins to consume the endosperm in its container in order for the new plant to start growing.