are we able to change chromasones in larger animals or cells,viruses and will there offspring be a completely different

Question: are we able to change chromasones in larger animals or cells,viruses and will there offspring be a completely different animal?
- Keywords:
  animal,
  chromasones,
  offspring,
  viruses
Asked by rtb96 to Katie on 19 Jun 2011.
- Katie Marriott answered on 19 Jun 2011:
  
  I don’t know! I am sure you cannot change the chromosomes of a species very much because I think it would die. It would not have the correct genes to code for certain enzymes (for example) that it needs to survive.
  
  I’m a chemist so I am not sure the workings of chromosomes and how changing them would affect the animal!

Question: are we able to change chromasones in larger animals or cells,viruses and will there offspring be a completely different animal?