Gene A converts compound A green to compound B blue Gene B c

Gene A converts compound A (green) to compound B (blue). Gene B converts compound B to compound C (red). These compounds determine the color of the individual. In a self cross of AaBb individuals, what proportion of blue to green offspring should be seen?

4 blue : 3 green

3 blue : 1 green

3 blue : 4 green

2 blue : 2 green

1blue : 3 green

Solution

b. 3 blue : 1 green

Compound A (green) -------GENE A--------->>>> Compound B (blue)
Compound B (blue) ------GENE B-------->>>> Compound C (red)
There are 9 organisms that are blue (able to produce Compound C)
There are 3 organisms that are green (only able to produce Compound B)

9:3 can be shortened to 3:1