If it were me, I would be interested in learning about if I had the Alzheimer's gene or not. Since it does run in my family, there is a strong likelihood that I am carrying it. Other things I might want to know is the probability I could develop cancer. My mother died of it 10 years ago and although I am more genetically like my father, there is still a chance I am carrying the genes for it. I do not smoke, nor engage in any other physical contributors to cancer (which is not a guarantee I will not get it), so environmentally induced cancer is a small possibility. If I do get it, it will be genetic. Thanks mom!
DNA replicates in the nucleus of the cell. An enzyme breaks the hydrogen bonds between the two strands of the double helix. When the nitrogen bases are exposed, free-floating nucleotides in the nucleoplasm attach themselves to the exposed bases. Remember that A always bonds with T and C always bonds ...
This solution explains how DNA replicates and how proteins are made. It also discusses how cells grow and divide, which when left unregulated, can be a cause for cancer.