Explaining the Beginnings of DNA?

A crucial element to appreciating, caring and providing for the needs of The Human Body, is first & foremost, to have some basic understanding of how the body is made up and its requirements in order for you to have a healthy, enjoyable, active and fulfilling life, as free from pains and diseases as possible.
Without knowing the why, what and how, it is very difficult to have the respect necessary to accomplish those goals.
But can these needs and functions be explained in a simple-to-understand way?
If we do not try, we will never know. So let’s begin at the beginning.
In the beginning there was a single cell. Sperm from the father fertilized an egg from the mother. This combination contains DNA from both the father and the mother.