1. The effects of the fur colour alleles can be further modified by a second gene which is not sex-linked. The allele r changes the brown colour to tan, and white colour to grey. Allele R has no effect on fur colour in rabbits. 

A grey coloured male rabbit was crossed with a roan female who is heterozygous for the second colour modifying gene. 

State the genotypes of both parents. 

Note that the symbol ^ can be used to denote superscript text.