The early stages of development refer to the initial phases of growth and change in living organisms, particularly during the embryonic and fetal periods in humans. This stage begins with fertilization, where a sperm cell merges with an egg cell, forming a single cell called a zygote. The zygote undergoes rapid cell division, eventually developing into a multi-cellular structure known as a blastocyst. During these early stages, the basic body plan is established, and vital organs begin to form. This process is influenced by genetic factors and environmental conditions. Proper nutrition and maternal health are crucial, as they can significantly impact the development of the embryo and later the fetus.