1 . Wie alt bist Du ? 2 . Du fhlst Dich bestens oder Dir geht es bestens ? <| sep |> Thank you ! My two favorites one . <| sep |> Waitaminute , how is this free ? Don ' t you have to buy decks 1 $ a pack ? <| sep |> Its a joke . <| sep |> Mistakes mutations happen occassionally during gene replication . Most of the time , mutations are bad they stop the gene working properly . However , because we have two copies of most genes , this isn ' t normally a problem if one copy is broken , we can just use the other one . These broken genes are passed on just the same as normal genes , but again it ' s not normally a problem because if you inherit a broken gene from your father , you ' ve probably also inherited a working version from your mother . The big problem with inbreeding is that your mother and father are related . Therefore , there is a good chance they carry the same broken genes . As such , there is a much higher than normal chance that you will inherit the broken gene from both your mother and your father , and not have a working version at all . There is another problem that in some cases it is better to have two different genes than the same gene heterozygote advantage i . e . there are lots of different working versions . This is particularly true for genes related to the immune system e . g . MHC genes where having different genes means you are resistant to a greater variety of diseases . As before , if your mother and father are closely related , it is much more likely that you will receive the same genes from both .