Question

if two parents each have a dominant and recessive gene for eye color and have a baby,how many possible combinations of genes could there be?

Answer 1

Say that the dominant gene is represented by B and the recessive gene is represented by b the combinations if using the Punnett square would be BB, Bb, Bb, and bb so 4 possible combinations and 3 possible nonrepetitive combinations- BB, Bb, and bb

Answer 2

I think you look to Genetics, DNA and Heredity .
MALES and FEMALES .
Women have 46 chromosomes  ( 44 autosomes plus two copies of the X
chromosome ) in their body cells. They have half of this or 22 autosomes plus 
an X chromosome in their egg cells. 
Men have 46 chromosomes ( 44 autosomes plus an X and a Y chromsomes )
in their body cells and have half of these 22 autosomes plus an X or Y chromosome in their sperm cells. 
when the egg joins with the sperm , the resultant baby has 46 chromosomes 
( with either an XX in a female baby or XY in a male baby ).