Box 1.

Examples of Genetics MCQs

1. Which of the following mutations is a point mutation that changes a codon specifying an amino acid into a stop codon?

A. Deletion C. Missense

B. Insertion D. Nonsense*

2. Mosaic individuals who have cells with different numbers of chromosomes are most likely caused by which of the events in cell division?

A. Failure of chromosome to replicate

B. Interference during the crossing over

C. Non-disjunction during meiosis

D. Non-disjunction during mitosis*

3. Taysach’s disease is an autosomal recessive disorder which is manifested in a person with homozygous recessive for the trait (tt). A couple who do not have Taysachs gave birth to a baby with Taysachs. Which of the following are the genotypes of the parents?

A. Tt x tt C. TT x Tt

B. Tt x Tt * D. TT x TT

4. A 28 year-old mentally retarded patient presents with hypotonia, obesity, short stature with small hands, feet, and mouth as well as impaired sexual development. His karyotype reveals deletion in the proximal arm of chromosome 15. Which among the following syndromes is the most likely diagnosis?

A. Angelman syndrome

B. Beckwith-Wiedemann syndrome

C. Prader-Willi syndrome *

D. Silver–Russell syndrome

5. Karyotyping can be used to diagnose which of the following genetic disorders?

A. Color blindness C. Edward’s syndrome*

B. Hemophilia D. Muscular dystrophy

6. A 36-year-old male’s family pedigree showed an inheritance of LQT1 (Romano-Ward Syndrome) and genetic test showed that he is a carrier of a mutated KCNQ1 gene but never develops features of the syndrome. Which of the following patterns of inheritance is shown in this case?

A. Autosomal dominant C. New mutation

B. Autosomal recessive D. Reduced penetrance*

7. To reduce the risk of having a child with a genetic disorder, genetic testing can be offered. Which of the following testing methodologies can be used to detect genetic changes in embryos that were created using in-vitro fertilization?

A. Carrier test C. Pre-natal test

B. New born screening D. Pre-implantation test*

8. A 20-year-old male presents with more than 100 colorectal polyps and a carrier of APC gene mutation on chromosome 5q21 resulting in an autosomal dominant condition. Which of the given types of CRC is most likely shown in this case?

A. Familial adenomatous polyposis*

B. Attenuated Familial adenomatous polyposis

C. MUTYH-associated polyposis

D. Hereditary Non-polyposis colorectal cancer

Note: An asterisk symbol (*) indicates the correct answer from the given choices.