Humans start off as a single fertilized cell. How does that one cell create multiple organs and organ systems to form a single human?
Cells are not differentiated and there are not special tissue types. All cells are the same with identical DNA and proteins navigate their way to the appropriate organs.
As cells replicate, the new cells only replicate small sections of DNA that they will need to be specialized as a new emerging tissue.
As cells replicate, new cells appear for specialized tissues
As the organism grows, different genes are turned on or off through cell differentiation
I already tried the second one and it was wrong