Genetics question

[Fraggr]

Kinda confused about symbols.

A question on my homework sheet says "in rabbits, the allele for brown coats is dominant to the allele for white coats. Write down suitable symbols for these two coat colours."

I am not sure if it should be BrBr whwh or Brbr whwh. Any help?

 

[Fraggr]

ah damn your edit!

lol I think it hit a shortcut for post thread.

 

[Fraggr]

I think these are the outcomes, using B as Brown and w as white.

BB - Brown
Bw - Brown
ww - White

But what would the brown parent have?

 

[Fraggr]

Hmm, well if both parents were Brown then they'd either have BB or Bw but they'd both pass on the B allele because it is dominant. If there was 1 Brown and 1 white parent they'd still have the B allele for a brown child. You'd need 2 white parents to have a white rabbit because it's the recessive gene.

I think.

I reread the question to myself, and I think it just wants to know what letter you should use for brown and white

Br/B and wh/w is the answer. I thought it was more complicated than it actually is...

 

[Fraggr]

You should always write the dominant gene as a capital letter with the recessive gene as the lower case letter used for the dominant gene. So if brown is dominant over white it should be written as Bb.

So you would have BB for Homozygous brown, Bb for Heterozygous brown and bb for Homozygous white.

Yeah, I know. I just had a moment of temporary retardation there.