Snape/Petunia Connection [was Snape's "Mind Set"]

[mitchbailey82]

No: HPFGUIDX 44578

--- In HPforGrownups at y..., "ats_fhc3" <the.gremlin at v...> wrote:
Though, what kind of genetics 
> produces fraternal boy and girl twins where the boy has black hair, 
> sallow skin, black eyes, a hooked nose, and a girl who has red hair 
> and green eyes?
> 

Now me:

Boy/girl twins can't identical twins (obviously), in boy girl twins 
only occur when 2 separate eggs are fertilised at the same time this 
means that they are produced not only by separate eggs but also by 
separate sperm. They are the same as any normal brother and sister 
genetically, the only difference is that they shared the womb at the 
same time. Many siblings have different characteristics (eg different 
hair colour, eye colour) you can often get one sibling that takes 
after the Dad and another that takes after the Mum. So it is possible 
to get two non-identical twins that look nothing like each other.



Michelle