Hello!
Let's define the following gene symbols:
Brown Body Color (Dominant): B
Black Body Color (Recessive): b
Red Eye Color (Dominant): R
Brown Eye Color (Recessive): r
To forecast all phenotypic outcomes of this cross, constructing a Punnett Square is helpful as it simplifies the process of analyzing dihybrid crosses involving two distinct traits.
Essentially, you combine each possible allele pair from one parent (BR, Br, br, bR) with each pair from the other parent.
See the attached image for better understanding.
The resulting phenotypic ratio from this cross is:
9 : 3 : 3 : 1
9 showing dominance for both traits
3 showing dominant eye color and recessive body color
3 showing dominant body color and recessive eye color
1 showing recessiveness for both traits
Genotypes and their Corresponding Phenotypes:
BBRR - Brown Body, Red Eyes
BBrR - Brown Body, Red Eyes
BBRr - Brown Body, Red Eyes
bBRR - Brown Body, Red Eyes
BbRR - Brown Body, Red Eyes
BBrr - Brown Body, Brown Eyes
bBrR - Brown Body, Red Eyes
bBRr - Brown Body, Red Eyes
BbrR - Brown Body, Red Eyes
BbRr - Brown Body, Red Eyes
bBrr - Brown Body, Brown Eyes
Bbrr - Brown Body, Brown Eyes
bbRR - Black Body, Red Eyes
bbrR - Black Body, Red Eyes
bbRr - Black Body, Red Eyes
bbrr - Black Body, Brown Eyes