MCQ 2016-17 MM Flashcards
Q1. John is a 45-year-old male and has noticed abnormal growth and bleeding of a mole on his arm. His doctor takes a biopsy of the mole and it turns out to be malignant. Some of the cancerous cells are sequenced and a variety of different somatic mutations are detected in key oncogenic genes. John’s maternal uncle experienced cancer but of a different type and is now in remission. How, and in whom would these somatic mutations in John’s biopsy have arisen? A. Meiotic division in John B. Meiotic division in one of John’s grand-parents C. Meiotic division in one of John’s parents D. Mitotic division in John E. Mitotic division in one of John’s parents
D. Mitotic division in John
Q2. As well as dividing inappropriately, cancer cells also go through a process of de-differentiation by which they become less specialized. Potency, in terms of cell differentiation, is a measure of the ability of a cell to produce different types of cells. In this context, how can the potency of the newly fertilized zygote be described? A. Impotent B. Multipotent C. Pluripotent D. Totipotent E. Unipotent
D. totipotent
Q3. You are working in a laboratory studying the fundamental elements of mammalian chromosomes. What role do telomeres play in a cell? A. They are the points at which cell replication initiates. B. They are the points at which mitotic spindle binds during cell division. C. They control condensation (folding) of DNA. D. They control the initiation of transcription. E. They maintain chromosome integrity during cell division.
E. They maintain chromosome integrity during cell division.
Q4. A 24-year-old woman is infected with human papillomavirus (HPV). A viral protein from HPV binds to p53 and inactivates it. This results in unregulated cell cycle progression. When bound to this viral protein, p53 is unable to induce the cellular event normally initiated in response to DNA damage. At what stage of the cell cycle does p53 normally play its regulatory role? A. G0 B. G1 C. G2 D. M E. S
B. G1 - allows or stops from progressing to S
Q5. A 56-year-old man is diagnosed with colon cancer. He is treated with irinotecan. This drug works by inhibiting an enzyme that is involved in the catalytic cutting and resealing of DNA ahead of the replication fork. What enzyme is this? A. DNA ligase B. DNA polymerase C. DNA primase D. Helicase E. Topoisomerase
D. Topoisomerase
Q6. In the laboratory you isolate a number of mature mRNA molecules after they exit the nuclear pore of a eukaryotic cell. Analysis of these molecules reveals that they all have the same component at their 5’ end. What is this component? A. A polyadenylation signal sequence B. A promoter region C. An upstream promoter element D. Methionine E. 7-methyl-guanosine
E. 7-methyl-guanosine
Q7.Jonny, aged 14, has developed acne. He is prescribed tetracycline, an antibiotic. What is the mechanism of action of this drug? A. Inhibition of bacterial DNA repair B. Inhibition of bacterial DNA replication C. Inhibition of bacterial protein translation D. Inhibition of bacterial transcription E. Inhibition of the bacterial cell cycle
C. Inhibition of bacterial protein translation
Q8. MicroRNAs (MiRs) are small strands of RNA (20-25 nucleotides) that regulate gene expression. They are transcribed from the DNA but are non-coding; that is, they don’t make any proteins. They can bind to specific mRNA sequences and their primary goal is to down regulate gene expression. What protein(s) process microRNAs in the cytoplasm to their mature form? A. Dicer B. DGCR8 C. DROSHA D. Exportin 5 E. RISC
A. Dicer
Q9. A 55 year-old woman is diagnosed as having breast cancer. Further analysis shows that both the epidermal growth factor 1 receptor (EGFR) and the tyrosine kinase c-Src are mutated in the tumour. c-Src has a mutation that makes it constitutively active. Therefore drugs targeting what activity of Src will be potentially beneficial in treating this patient? A. Addition of acetyl groups to its substrate B. Addition of farnesyl groups to its substrate C. Addition of methyl groups to its substrate D. Addition of phosphates to its substrate E. Addition of ubiquitin to its substrate
D. Addition of phosphates to its substrate
Q10. A 55-year-old man is diagnosed with Parkinson’s disease. Genetic analysis demonstrates a mutation in PARKIN resulting in inactivation of the protein Parkin. This results in accumulation of several brain specific proteins because they are not degraded, which may be important in driving the pathology of this disease. E3 ubiquitin ligases such as Parkin transfer multiple ubiquitin chains on to what residue? A. Arginine B. Lysine C. Proline D. Serine E. Threonine
B. Lysine
Q11. You are working in a clinical genetics laboratory and are asked to sequence the CFTR gene as part of a diagnostic test for a suspected case of cystic fibrosis. You observe the following sequence in the patient, who appears to be variable at this locus. 5’ – GGTGA(TAG)5GGCACTT – 3’ What type of genetic variation is indicated in this sequence? A. Copy number variant B. Inversion C. Microsatellite D. Single nucleotide polymorphism E. Translocation
C. Microsatellite
Q12. The polymerase chain reaction (PCR) is used in a range of different clinical applications including diagnosis of genetic diseases, identification of pathogenic agents and paternity testing. Components necessary for PCR include 1) thermostable DNA polymerase; 2) dNTPs + Mg2+; 3) oligonucleotide primers. What other key component is required for successful PCR? A. DNA template B. Hybridisation matrix C. Plasmid vector D. Radioisotope E. Restriction endonucleases
A. DNA template
Q13. The DNA sequence was determined for a sample extracted from a patient’s tumour. DNA was analysed using a method which involved the use of DNA fragmentation and cluster generation (employing amplification of DNA). Which sequencing method was most likely employed to determine the tumour DNA sequence? A. Array comparative genomic hybridization (array CGH) B. Fluorescence in-situ hybridization (FISH) C. Illumina (Solexa) D. Polymerase Chain Reaction (PCR) E. Sanger
C. Illumina
Q14. You are working in a clinical genetics laboratory, studying a particular case of Down syndrome that presents with relatively mild symptoms. You notice that the affected child displays mosaicism for trisomy 21. What form of cell division, and in what location, would the non-disjunction event most likely have occurred? A. Meiosis in child, after birth. B. Meiosis in embryonic development of child C. Meiosis in parents of child D. Mitosis in embryonic development of child E. Mitosis in parents of child
D. Mitosis in embryonic development of child
Q15. Beta thalassaemia presents a significant health burden in the Gulf States region of the Middle East. You are interested in determining the frequency of heterozygote carriers in the population. What component of the Hardy-Weinberg Equilibrium equation (p2+2pq+q2=1) represents the heterozygous state? A. 2pq B. p C. p2 D. q E. q2
A. 2pq
John, 27-years-old, went to visit his GP regarding evidence of a hereditary disorder in his family. He wishes to understand his risk of developing the disease. The GP took a family history and sketched a pedigree. His father was killed in a road traffic accident when John was young and therefore he has no information on whether his father might or might not have developed the disease.
Q17. From the pedigree below what is the most likely mode of inheritance for this disorder in this family?
A. Autosomal dominant
B. Autosomal recessive
C. Mitochondrial
D. X-linked dominant
E. X-linked recessive
A. Autosomal dominant
