The benefits of antioxidants are very important to good health, because if free radicals are left unchallenged, they can cause a wide range of illnesses and chronic diseases. The human body naturally produces free radicals and the antioxidants to counteract their damaging effects.
Supplement. When a pair or set of genes are on the same chromosome, they are usually inherited together or as a single unit. For example, in fruit flies the genes for eye color and the genes for wing length are on the same chromosome, thus are inherited together.
Why might gene duplication allow for generation of more genetic variability? The second copy of the gene could be expressed under different regulation. The second copy of the gene could accumulate mutations which would be lethal if only one copy were present. The second copy of the gene could be deleted without effect on the organism.