It all comes down to what genes they are expressing based on what transcription factors are present. Due to genomic equivalence, every cell in the body has the "program" to make everything, but when cells differentiate they take on specific roles and express specific genes which produce specific proteins that do specific functions. Haha, yes, I know I just said specific multiple times. But that's the point. Different cells use the same DNA to perform different functions.
You could get into a much longer genetic conversation about histone acetylation/methylation/phosphorylation, enhancer and silencer sequences, DNA methylation, activator and repressor proteins, etc. But that would take way to long to explain here.
Answers & Comments
Verified answer
Hello!
It all comes down to what genes they are expressing based on what transcription factors are present. Due to genomic equivalence, every cell in the body has the "program" to make everything, but when cells differentiate they take on specific roles and express specific genes which produce specific proteins that do specific functions. Haha, yes, I know I just said specific multiple times. But that's the point. Different cells use the same DNA to perform different functions.
You could get into a much longer genetic conversation about histone acetylation/methylation/phosphorylation, enhancer and silencer sequences, DNA methylation, activator and repressor proteins, etc. But that would take way to long to explain here.
Hope this helps!
Basically, it is determined by what it's been programmed to replicate.