QCM Part 1 PDF

**Part 1: General Concepts of Cancer** **1. What is the earliest known documentation of cancer?**\ a. Edwin Smith Papyrus (\~3000 BC)\ b. Hippocratic Corpus (\~400 BC)\ c. Evidence from the 17th century\ d. Modern pathology textbooks\ **Answer:** a **2. What is the definition of cancer?**\ a. Unco...

**Part 1: General Concepts of Cancer** **1. What is the earliest known documentation of cancer?**\ a. Edwin Smith Papyrus (\~3000 BC)\ b. Hippocratic Corpus (\~400 BC)\ c. Evidence from the 17th century\ d. Modern pathology textbooks\ **Answer:** a **2. What is the definition of cancer?**\ a. Uncontrolled growth of cells that form a mass and invade nearby tissues.\ b. Overactive immune cells attacking healthy tissue.\ c. Normal cell proliferation in response to growth signals.\ d. Controlled growth of cells in tissues.\ **Answer:** a **3. Which of the following is NOT a recognized cause of cancer?**\ a. Lifestyle factors\ b. Chemical carcinogens\ c. Viral infections\ d. High-fiber diets\ **Answer:** d **4. What is the median age for cancer diagnosis?**\ a. 40 years\ b. 50 years\ c. 66 years\ d. 75 years\ **Answer:** c **5. Which type of cancer-causing agents includes asbestos and UV radiation?**\ a. Biological carcinogens\ b. Chemical carcinogens\ c. Physical carcinogens\ d. Genetic predisposition\ **Answer:** c **Part 2: Cell Cycle and Checkpoints** **6. What is the purpose of the G1/S checkpoint?**\ a. To ensure DNA replication is complete.\ b. To verify DNA is intact and nutrients are sufficient for replication.\ c. To confirm all chromosomes are attached to spindle fibers.\ d. To signal cytokinesis.\ **Answer:** b **7. What triggers the activation of Cdk4-6/Cyclin D complexes during the G1 phase?**\ a. Mismatch repair activation\ b. Growth factor signaling through pathways like PI3K/Akt/mTOR\ c. Degradation of securin\ d. Centrosome duplication\ **Answer:** b **8. Which transcription factor is released when Rb is phosphorylated?**\ a. Myc\ b. E2F\ c. p21\ d. Cdk2\ **Answer:** b **9. What is the role of Cdk2/Cyclin A in the S phase?**\ a. To degrade securin and activate separase.\ b. To initiate DNA replication by recruiting helicase.\ c. To phosphorylate condensins for chromatin condensation.\ d. To trigger centrosome duplication.\ **Answer:** b **10. Which checkpoint verifies that DNA replication is complete and error-free before mitosis?**\ a. G1/S checkpoint\ b. G2/M checkpoint\ c. Metaphase checkpoint\ d. S-phase checkpoint\ **Answer:** b **Part 3: DNA Repair Mechanisms** **11. Which DNA repair pathway is highly accurate and relies on a complementary DNA strand?**\ a. Mismatch repair (MMR)\ b. Homologous recombination (HR)\ c. Non-homologous end joining (NHEJ)\ d. Base excision repair (BER)\ **Answer:** b **12. What protein recognizes mismatched bases during DNA replication?**\ a. Ku proteins\ b. MutS proteins\ c. BRCA1\ d. Cdc25\ **Answer:** b **13. Why is NHEJ considered error-prone?**\ a. It does not restore the original genetic sequence.\ b. It introduces double-strand breaks.\ c. It only repairs single-strand DNA damage.\ d. It depends on homologous DNA templates.\ **Answer:** a **14. What role does BRCA1 play in DNA repair?**\ a. It promotes NHEJ to repair DNA breaks.\ b. It stabilizes the repair complex for homologous recombination.\ c. It inhibits Cdk2/Cyclin A activity.\ d. It activates the ATR/ATM pathway for checkpoint control.\ **Answer:** b **15. In which repair pathway are Ku proteins involved?**\ a. Mismatch repair (MMR)\ b. Non-homologous end joining (NHEJ)\ c. Homologous recombination (HR)\ d. Base excision repair (BER)\ **Answer:** b **Part 4: Tumor Suppressor Genes and Proto-Oncogenes** **16. How does a proto-oncogene contribute to cancer when mutated?**\ a. It becomes hypo-activated.\ b. It becomes an oncogene that promotes uncontrolled cell growth.\ c. It suppresses apoptosis.\ d. It repairs double-strand breaks.\ **Answer:** b **17. What happens to tumor suppressor genes in cancer?**\ a. They become overactivated.\ b. They are mutated or inactivated.\ c. They directly activate oncogenes.\ d. They promote DNA replication.\ **Answer:** b **18. Which is an example of a tumor suppressor gene?**\ a. Myc\ b. BRCA1\ c. Cyclin D\ d. Ku proteins\ **Answer:** b **19. What is the inheritance pattern of BRCA1/2 mutations?**\ a. Autosomal recessive\ b. Autosomal dominant\ c. X-linked\ d. Mitochondrial inheritance\ **Answer:** b **20. Which of the following is a hallmark of cells with defective BRCA1/2?**\ a. Increased homologous recombination repair\ b. Genomic instability due to impaired DNA repair\ c. Enhanced apoptosis signaling\ d. Reduced cell cycle progression\ **Answer:** b **Part 5: Cancer Therapies and Mechanisms** **21. What is the therapeutic mechanism of PARP inhibitors?**\ a. Enhancing HR repair in tumor cells\ b. Blocking single-strand break repair, leading to cell death in HR-deficient cells\ c. Promoting checkpoint activation\ d. Inducing tumor suppressor gene expression\ **Answer:** b **22. What is the concept of synthetic lethality in cancer treatment?**\ a. Killing tumor cells by enhancing tumor suppressors.\ b. Exploiting specific vulnerabilities in cancer cells that rely on defective pathways.\ c. Repairing defective DNA in cancer cells.\ d. Activating proto-oncogenes to kill tumors.\ **Answer:** b **23. How does p53 respond to DNA damage?**\ a. By promoting DNA replication.\ b. By initiating apoptosis or cell cycle arrest.\ c. By repairing single-strand breaks.\ d. By activating Cyclin B.\ **Answer:** b **24. What is the role of Myc in cancer?**\ a. It suppresses oncogene expression.\ b. It regulates the cell cycle and is hyper-activated in cancer.\ c. It stabilizes the DNA repair complex.\ d. It promotes apoptosis.\ **Answer:** b **25. What happens to cells at the metaphase-to-anaphase checkpoint if chromosomes are not properly attached to spindle fibers?**\ a. Cdc25 activates the checkpoint.\ b. Mad2 inhibits APC/C, halting progression.\ c. E2F transcription factor is activated.\ d. PARP inhibitors are activated.\ **Answer:** b **Part 6: Miscellaneous** **26. Which phase is characterized by DNA synthesis and replication?**\ a. G1 phase\ b. S phase\ c. G2 phase\ d. M phase\ **Answer:** b **27. What enzyme complex promotes chromatin condensation in mitosis?**\ a. Cdk1/Cyclin B\ b. Cdk2/Cyclin A\ c. BRCA2\ d. APC/C\ **Answer:** a **28. Which cyclin activates Cdk4/6 in the G1 phase?**\ a. Cyclin A\ b. Cyclin B\ c. Cyclin D\ d. Cyclin E\ **Answer:** c **29. What molecular pathway does Ras activate in response to growth factors?**\ a. ATR/ATM pathway\ b. MAPK pathway\ c. Mismatch repair pathway\ d. NHEJ pathway\ **Answer:** b **30. Which type of DNA damage is most effectively repaired by homologous recombination?**\ a. Double-strand breaks\ b. Single-strand breaks\ c. Oxidized bases\ d. DNA mismatches\ **Answer:** a