James has one brown-eye gene and one blue-eye gene. His wife Carolyn also has one brown-eye gene and one blue-eye gene. What is the chance that their child could have blue eyes?

Question

Quizplus · Accepted Answer

The chance of their child having blue eyes is one in four. This is because each parent has a 50% chance of passing on either the brown-eye gene or the blue-eye gene. When both parents pass on the blue-eye gene, the child will have blue eyes. The possible combinations are brown-brown, brown-blue, blue-brown, and blue-blue, with only the last combination resulting in blue eyes.

James Has One Brown-Eye Gene and One Blue-Eye Gene