Medical Genetics: Inheritance of Genetic Disorders (Dominant, Recessive and X-Linked)


Lecture Notes and Multiple Choice Question  on Inheritance Pattern of Genetic Disorders





Multiple Choice Questions on Inheritance Pattern of Genetic Disorders

1) Which of the following statement is true regarding the Mendelian Theory of Inheritance? 
a) The genotype ratio for the second generation is 1:2:1
b) The phenotype ratio for the second generation is 3:1
c) The inheritance pattern assume one gene-one protein phenomenon
d) All of the above

2) Which of the following statements are true regarding the dominant traits?
a) One dominant allele (heterozygotes) is sufficient to show the dominant trait
b) Both dominant alleles  (homozygous) are required to show the dominant trail
c) Heterozygotes (individuals with one allele) are generally carriers. 
d) None of Above

3) Which of the following statements are true regarding the recessive traits?
a) One recessive allele (heterozygotes) is sufficient to show the phenotypic trait
b) Both recessive alleles  (homozygous) are required to show the phenotypic trail
c) Heterozygotes (individuals with one allele) are generally carriers. 
d) Option a & b
e) Option a & c

4) Identify the correct statement regarding autosomal dominant disorders.
a) At least one parent with the heterozygous mutation is sufficient for the showing the phenotype in progeny
b) The affected individuals are always homozygous for the mutant allele
c)  Often heterozygotes (individuals with one allele) are generally carriers.
d) None of the above

5) Identify the correct statement regarding autosomal recessive disorders.
a) At least one parent with the heterozygous mutation is sufficient for the showing the phenotype in progeny
b) The affected individuals are always homozygous for the mutant allele
c)  Often heterozygotes (individuals with one allele) are generally carriers.
d) None of the above

6)  Which of the following statement is false regarding the X-linked recessive inherited disorders?
a) The daughters from affected fathers are generally carriers
b) The mutant allele in sons are inherited from the mother
c) The mutant allele in sons are inherited from the father
d) None of the above

7)  Which of the following statement is true regarding the X-linked dominant inherited disorders?
a) The daughters from affected fathers are generally carriers
b) The mutant allele in affected sons are inherited from the mother
c) The mutant allele in affected sons are inherited from the father
d) None of the above

8) Identify the pattern of inheritance from the linkage below


a) Autosomal Dominant 
b) Autosomal Recessive
c) X-linked Recessive 
d) X-linked Dominant

9) Identify the pattern of inheritance from the linkage below

a) Autosomal Dominant 
b) Autosomal Recessive
c) X-linked Recessive 
d) X-linked Dominant

10) The following statements are true regarding the inheritance of disorders of mitochondrial DNA
a) The disorders of mitochondrial DNA are inherited from males
b) The disorders of mitochondrial DNA are inherited from females
c) The penetrance of the disease is tightly variable
d) None of the above

11) Which of the following genetic disorder is inherited in an autosomal recessive manner?
a) Sickle cell anemia 
b) Achondroplasia
c) Hemophilia 
d) Leber's Hereditary Optic Neuropathy

12) Achondroplasia is the hyperactive mutation of the FGFR3 receptor, which of the following is the possible pattern of inheritance 
a) Autosomal Dominant 
b) Autosomal Recessive
c) X-linked Recessive 
d) X-linked Dominant

Answers 
1-d) All of the above
2-a) One dominant allele (heterozygotes) is sufficient to show the dominant trait
3- e) Option a & c
4-a) At least one parent with the heterozygous mutation is sufficient for the showing the phenotype in progeny
5-b) The affected individuals are always homozygous for the mutant allele
6-c) The mutant allele in sons are inherited from the father
7-b) The mutant allele in affected sons are inherited from the mother
8-b) Autosomal Recessive
9-c) X-linked Recessive
10- Option b & c 
11-a) Sickle cell anemia
12-a) Autosomal Dominant 

Comments