Answer:
The adult human forms from the single-celled zygote.
Explanation:
The cell theory was put by Schleiden and Schwann. It is said that all the living organisms made up of from a single cell. It means the cell is the structural and fundamental unit of life. In human beings, it is also seen. The human comes from the fertilization of haploid sperm and ovum. The zygote is the single fertilized cell that undergoes cell division to form multicellular organisms. The single-cell zygote becomes a multicellular gastrula and forms the 3 germ layers. These three germ layers later form different tissues and organs by organogenesis. This happens due to the mitotic cell division. Thus an adult human will form and the cell division continues till the death of the individual. This process indicates how a single-celled zygote forms the multicellular human.
