6 h 9 janv. 2018 ans - cells begin differentiation to become different tissues because it occurs many times during the development of a multicellular organism as the organism changes from a single zygote to a complex system of tissues and cell types.
Ajouté au bande de temps:
Date:
6 h 9 janv. 2018 ans
Maintenaint
~ Il y a 7 ans et 9 mois