Free earlobes are dominant to attached ear lobes and brown eyes are dominant to blue eyes. Ricardo has brown eyes and attached ear lobes. Ricardo's mother has blue eyes and free ear lobes. Ricardo's partner, Shanteel, has blue eyes and free ear lobes. Shanteel's mother has brown eyes and attached ear lobes. What is the probability that Ricardo and Shanteel will have a child who has blue eyes and attached ear lobes?
A) 100 percent
B) 75 percent
C) 50 percent
D) 25 percent
E) 0 percent

Question

Quizplus · Accepted Answer

According to the given information, Ricardo is heterozygous for both traits (BbEe), while Shanteel is homozygous recessive for eye color and heterozygous for earlobe attachment (bbEe). 
The Punnett Square for their offspring is:

|   | B | b |
|---|---|---|
| e |Be |be |
| e |Be |be |

Therefore, there is a 25% probability that their child will have blue eyes and attached earlobes.

Free Earlobes Are Dominant to Attached Ear Lobes and Brown