Im not very sure this question belongs to this forum or genetics but since developmental biology is not a forum so i guess this is the right place to ask.
I have this doubt question eating up my head for almost an year,hope ill find an answer:
The genome of each and every cell inside our body is same.How a liver cell differs from a kidney cell or a skin cell is because every different cell has different genes activated than the other.Say a gene "X" will be active in skin cell and gene "y" is up regulated in liver cell and thus imparting the respective characters.
Now when these cells divide they will give rise to two daughter cells which will already have that very gene activated (of course same as the parent cell)which makes it a liver or a kidney or any cell for that matter because they know it from their parent cell.
But when we start from the zygote,and cells go through morula ,gastrula,blastula stages,and the three germ layers,how does the cell know at that time which genes to activate in order to make a given cell a neuron,cardiac cell.
I mean every cell has the exact same genome.Nothing in the cell knows for a cell to become a neuron which nucleotide sequence is responsible.How does it recognise gene "x" "y" or any other? The cell doesnot know that "x" will make a skin cell or "y" will make a liver cell.Its all the same,its only a sequence. How does it know then?

btw im not very sure whether:
I have conveyed what i wanted to ask clearly
i have asked the thing i wanted to. 😐