If the gene for blue eyes is recessive, and if John's mother and father both have blue eyes, we know that John:
A) will be homozygous on the eye color trait
B) will be heterozygous on the eye color trait
C) will have a 50% chance of having blue eyes
D) will have a 25% chance of having blue eyes

Question

Quizplus · Accepted Answer

Normally, recessive traits are only expressed when a person has inherited two recessive genes. In this example, one should assume that both the mother and father, having blue eyes, have two recessive genes. It follows that each would have had to contribute a recessive gene, resulting in John being homozygous on the eye color trait.

If the Gene for Blue Eyes Is Recessive, and If