Answer:
Grandmother - grandson.
Step-by-step explanation:
The genetic relationship between individuals Level 1 - 2 and Level III - 4 is grandmother - grandson because the gap between individuals is two generations. The circular shape represents male while on the other hand, the square shape represents female individual. So we know that in the first level, the second individual is square which means it is a female while on the other hand, in the third level, the fourth individual is circular that represents male so it is a relationship of grandmother - grandson.