Principles of Inheritance & Genetic Counseling MCQ Quiz | Genetics

1. A couple has a child with an autosomal recessive disorder. What is the probability that their next child will be a carrier for the disorder?

2. Huntington’s disease is an autosomal dominant disorder. If an affected heterozygous father and a normal mother have a child, what is the chance the child will inherit the disease?

3. Red-green color blindness is an X-linked recessive trait. A color-blind man marries a woman who is a carrier. What is the probability of them having a color-blind son?

4. The phenomenon where a single gene mutation affects multiple phenotypic traits is known as:

5. In a pedigree, a trait appears in every generation and affects both males and females equally. It is transmitted from an affected father to his son. What is the most likely mode of inheritance?

6. A genetic disorder is caused by a mutation in mitochondrial DNA. If an affected mother and an unaffected father have children, which of their offspring will be affected?

7. The percentage of individuals with a specific genotype who show the expected phenotype is referred to as:

8. Phenylketonuria (PKU) is an autosomal recessive disorder. The carrier frequency in a population is 1/50. According to the Hardy-Weinberg principle (assuming p ≈ 1), what is the approximate incidence of the disease (q²) in this population?

9. Which of the following is a primary indication for prenatal genetic counseling?

10. Uniparental disomy refers to a situation where:

11. In genetic counseling, the principle of non-directiveness means:

12. A characteristic feature of X-linked dominant inheritance is:

13. Cystic fibrosis is an autosomal recessive condition. Two unaffected parents have a child with cystic fibrosis. What is the probability that their phenotypically normal daughter is a carrier?

14. Angelman syndrome and Prader-Willi syndrome are classic examples of disorders resulting from:

15. In a pedigree analysis, consanguineous marriage is often associated with an increased incidence of:

16. Duchenne Muscular Dystrophy (DMD) follows which pattern of inheritance?

17. Variable expressivity is a term used to describe:

18. Which of the following is NOT a component of the genetic counseling process?

19. A man with Hemophilia A (X-linked recessive) marries a woman who is not a carrier. What is the risk for their children?

20. The Hardy-Weinberg law assumes which of the following is NOT occurring in a population?

21. The presence of two distinct cell populations with different karyotypes in a single individual, derived from a single zygote, is called:

22. In multifactorial inheritance, the recurrence risk for first-degree relatives of an affected individual is approximately:

23. What is the purpose of a pedigree chart in genetics?

24. A woman is a known carrier for an autosomal recessive condition. Her partner’s family has no history of the condition, and the population carrier frequency is 1/100. What is the a priori risk of them having an affected child?

25. Which genetic concept explains why some individuals with the genotype for a dominant disorder like Marfan syndrome show severe symptoms while others have very mild features?