Answer:
Given that, both parents are heterozygous. Now, the chances for one child to inherit one defective gene from each parent = ½*1/2 =¼.
Similarly, the probability of being affected by albinism =Probability of inheriting one defective gene from each parent = ½*½ = ¼
The probability of not being affected = 1- the probability of being affected = 1-1/4 = ¾.
Now, the chances of not being affected by both albinism and sickle cell anemia = ¾*3/4 = 9/16.
The probability of neither twins be affected = 9/16*9/16 =81/256.
Explanation: