Reverse transcriptase is an enzyme found in association with retroviral activity. it has the property of

In fact it is not just nuclear fusion and fission that  can  transform  matter  (or mass)into energy. any time  energy  is produced, some small amount of  matter  or mass isconverted into energy.

The principle of independent assortment describee how different genes independently separate from one another when reproductive cells develop.

  eukaryotic cells may arise from sexual reproductions, resulting in more genetic variation  i would say that is the answer