Question

all our body cells have same DNA, then why a neuron can not produce insulin ?​

Answer 1

Hey mate!

Our body has same DNA but different genes are present in different DNA which controlles different traits.

Answer 2

It sounds like you are already well aware of the fact that every cell in our body has the same set of genes. This is because all of the cells in our bodies start from a single fertilized egg.

With few exceptions, all cells in a person’s body have the same DNA and genes. As cells divide and grow different genes are expressed, resulting in different cell types. Those cells then produce a variety of proteins specific to the cells they form resulting in most of our chemistry. In general, the same is true for all cell-based life on earth.