A geneticist is studying a trait that is caused by an autosomal dominant gene. If a woman with the dominant gene has a child with a man who has no copies of the dominant gene, what is the probability that the child will exhibit the dominant trait?

Core Concept

Since the dominant gene is autosomal, the child can inherit the dominant gene from the mother. However, the child will also inherit the recessive gene (no copies of the dominant gene) from the father. The probability that the child will exhibit the dominant trait is 50% because the child has a 50% chance of inheriting the dominant gene from the mother. Option A is incorrect because the child can still inherit the dominant gene from the mother. Option C is incorrect because the child cannot inherit two copies of the dominant gene (one from the mother and one from the father). Option D is incorrect because the child has a 50% chance of not inheriting the dominant gene from the mother.