What does the variability of genetic diversity mean and provide 3 examples? !

The variability of genetic diversity means the different genetic characteristics which are present in organisms of  species. These variations allow organisms of a species to be better adapted to an environment. Those organisms with better genetic characteristics survive and pass on their genes to their offsprings.

For example,

due to the fact that it skipped a generation we can tell it is definitely not a dominant trait, therefore it must be recessive. i think this is right let me know!

explanation:

that is wrong, its not thymus.