From the beginning of the ninth week through birth, an individual is known as a **fetus**. During this stage of development, major organs and structures continue to grow and mature. The fetus begins to resemble a human more closely, with distinct facial features, limbs, and internal organs forming. At this stage, the focus is on further development and growth rather than the initial formation of basic structures.
The **zygote** stage occurs right after fertilization when the egg is fertilized by the sperm. This is the beginning of development. The **embryo** stage follows the zygote and lasts until about the end of the eighth week of pregnancy. During this time, the basic structures and organs of the body start to form.
The term **preembryo** is not a commonly used scientific classification and is not recognized in mainstream embryology. It is often used in more casual or non-scientific contexts to refer to the early stages of development before the embryo forms.
So, to sum up, from the beginning of the ninth week through birth, the individual is known as a **fetus**, which represents the stage of development characterized by further growth and maturation of organs and features.
