Which of the following statements about dominant and recessive diseases is true?
A) Children who inherit the dominant allele rarely develop the disorder.
B) Males are more likely than females to inherit recessive disorders carried on the autosomes.
C) Only rarely are serious diseases due to dominant alleles.
D) The recessive allele has no effect on the individual's characteristics.

Question

Quizplus · Accepted Answer

Dominant diseases occur when even one copy of the disease-causing gene is present, whereas recessive diseases require two copies of the disease-causing gene. Therefore, dominant diseases are less common because they generally occur only when one parent carries the disease-causing gene. Additionally, many serious diseases are caused by recessive alleles (such as cystic fibrosis or sickle cell anemia), so statement D is incorrect. Statement A is also incorrect because children who inherit the dominant allele have a 50% chance of developing the disorder, depending on whether the other parent also carries the gene. Finally, statement B is incorrect because males and females are equally likely to inherit recessive disorders carried on the autosomes.

Which of the Following Statements About Dominant and Recessive Diseases