Help me draw punnett grid!

[allthebest]

So the question is:

In cats, the allele for curled ears (C) is dominant over the allele for normal ears (c). The allele for black colour (B) is dominant over the allele for grey colour (b). A cross occurs between two cats that are both heterozygous for these unlinked traits.
Using a Punnett grid, predict the ratio of phenotypes of offspring in the next generation.

 

I'm so confused about the genotypes and how it should be drawn. A drawing will really help.

thank you.

[Martijn.S]

First; dihybrid cross is only in HL, monohybrid cross is SL.

Unfortunately, I can't draw a Punnett grid for you, considering I would be doing your work, but I can give you this information:

Since the traits are unlinked, you can already guess that you should end up with a 9:3:3:1 ratio.

Here are a couple of pages from the Oxford Biology study guide, which talk about these types of crosses.

monohybrid cross.pdf talks about monohybrid crosses and how to draw a Punnett grid.
dihybrid cross.pdf talks about dihybrid crosses and how you can expect the 9:3:3:1 ration from the cross you did.

Edit: I just realised you already passed your exams. Nevertheless, I hope it helps and that others can also use this.

Edited September 3, 2017 by Martijn.S