Is it multiple choice? I believe it's brain, but I could be wrong.
Given that Sheena's ball is a sphere, its volume can be obtained by using the formula: V_ball = (4/3)*pi*r^3, where, r is the radius of the sphere. Since the ball is 24 cm across, this means that the radius is half of the diameter which is equal to 12 cm. Thus, the volume of the ball is equal to 7238.2295 cm^2.
The allele would be called codominant
When a dominant and recessive allele exist in an organism, only the dominant allele will be expressed. Dominant allele always mask the recessive because the gene code a protein while recessive gene doesn't. When both gene code a protein, they will be codominant and both gene will be expressed. The result could be a mixed effect. In this case, the purple is mixed color of red and blue.
A the concentration gradient!