The term is a cell culture. When they get a single infected cell and put it in a nutrient solution and then that one cells develops and reproduces.
From an oocyte a blastocyte appears, then a zygote.
differentiation
differentiation
differentation
cell culture
differentiation
differentiation
differentiation
differentiation
differentiation
differentiation
differentiation
differentiation
differentiation
differentiation
differentiation
differentiation
differentiation