Science
Human body is made up of organic compounds. ie; compounds whose basic structure is made up of carbon,hydrogen and oxygen. Let us say, hypothetically, that human body contains all the elements in the periodic table.
We know that all the atoms of all the elements in the nature is made up of sub-atomic particles. And the nature of all the sub-atomic particles are still not understood clearly. But we can say that their exact nature cannot be defined in a concrete fashion which we are so used to, when learning science.
For example -Their position in space and their speed at a particular time cannot be known simultaneously (A paradoxical situation first conceived by Heisenberg).

So all the stuff that you see in this nature is made up of particles about which we cannot say anything solidly.

So when I die, my body desintagrate, and all the atoms and their constituents will go back to soil. Plants growing in this soil will absorb me and sprout leaves and fruits. Which, my children and their friends consume and grow. This cycle goes on and on.

Vedantam
Advaita vedantam says that all is made up of the same stuff and all that you see and feel exist only in your perception. What you should do is to release your self from this perceptionogenic maya to the world of absolute truth.Which cannot be explained or taught, but only experience by the one who is detached from the temptations of the senses.
So for a vedanti there is no difference between a tree and woman. For him everything perceived is a phenomena in the eternal flux of a common energy. slcw