Medical Microbiology Q&A Guide

** **BACHELOR OF MEDICINE AND BACHELOR OF SURGERY (MBChB) DEGREE** **UNIT CODE:** MDBS 3101**UNIT TITLE:** Parasitology / Entomology / Bacteriology**YEAR 3, PAPER 1****DATE:** 3rd July, 2018 – 8.00 a.m.**TIME:** 3 Hours --- ### INSTRUCTIONS: - Answer **all questions** in Sections A and B. - Answer **any two (2)** questions in Section C. - ## SECTION A: MULTIPLE CHOICE QUESTIONS ### Question 1 **What kinds of roaches might you expect to encounter in Athens?** **A) ** German roaches** B) ** American roaches** C) ** Smokey brown roaches** D) ** All of the above** E)** None of the above **Answer:** D) All of the above **Explanation:** Athens, with its Mediterranean climate and urban environment, supports multiple cockroach species including German roaches (most common indoor species), American roaches (prefer warm, moist areas), and Smokey brown roaches (outdoor species that enter buildings). --- ### Question 2 **What is the main advantage of using larval control against mosquitoes?** **A) ** Control will supplement natural control** B) ** Larvae are restricted to confined aquatic habitats that can be treated** C) ** Larval habitats do not support sensitive other organisms** D) ** All of the above** E)** None of the above **Answer:** B) Larvae are restricted to confined aquatic habitats that can be treated **Explanation:** Larval control is advantageous because mosquito larvae are confined to specific aquatic breeding sites (pools, containers, marshes) making them easier to target with larvicides or environmental management compared to flying adult mosquitoes that are widely dispersed. --- ### Question 2 **If you found lice eggs (nits) in someone's clothing, what species would they most likely be from?** **A) ** Crab lice (Pthirus pubis)** B) ** Head lice (Pediculus capitis)** C) ** Body lice (Pediculus humanus)** D) ** Hog lice** E)** All of the above **Answer:** C) Body lice (Pediculus humanus) **Explanation:** Body lice (Pediculus humanus corporis) are the only lice species that lay their eggs (nits) on clothing fibers, particularly along seams of garments. Head lice attach nits to hair shafts, while crab lice attach to coarse body hair. --- ### Question 3 **What are effective non-pesticide ways to control problems from cockroaches?** **A) ** Store food in plastic containers** B) ** Clean your kitchen counter tops nightly** C) ** Seal up cracks and seams around pipes and cabinets** D) ** All of the above** E)** A and C **Answer:** D) All of the above **Explanation:** Integrated pest management for cockroaches includes removing food sources (sealed containers), eliminating food residues (cleaning), and blocking entry points (sealing cracks). All these methods work together to make environments less suitable for cockroach survival and reproduction. --- ### Question 4 **The pupal stage is found in:** **A) ** Incomplete metamorphosis** B) ** Complete metamorphosis** C) ** Both incomplete and complete metamorphosis** D) ** Neither incomplete nor complete metamorphosis** E)** None of the above **Answer:** B) Complete metamorphosis **Explanation:** The pupal stage only occurs in complete metamorphosis (holometabolism) where insects go through egg → larva → pupa → adult stages. Incomplete metamorphosis (hemimetabolism) has only egg → nymph → adult stages with no pupal stage. --- ### Question 6 **How does insecticide resistance develop?** **A) ** By using Integrated Pest Management practices** B) ** By using low doses of insecticides** C) ** By using high or prolonged doses of insecticide** D) ** B and C** E)** None of the above **Answer:** D) B and C **Explanation:** Insecticide resistance develops through both low doses (sub-lethal doses allow resistant individuals to survive and reproduce) and high/prolonged doses (intense selection pressure favors resistant genotypes). IPM actually helps prevent resistance by reducing selection pressure. --- ### Question 8 **Ceratopogonidae larvae are found in:** **A) ** Freshwater marshes** B) ** Salt marshes** C) ** Wet muddy areas around cattle watering tanks** D) ** All of the above** E)** A and B **Answer:** D) All of the above **Explanation:** Ceratopogonidae (biting midges/no-see-ums) larvae are semi-aquatic and found in various moist environments including freshwater marshes, salt marshes, and muddy areas around water sources. Different species adapt to different salinity and moisture conditions. --- ### Question 9 **Integrated Pest Management:** **A) ** Relies solely on pesticides** B) ** Relies solely on biological and natural control** C) ** Considers the biology of the target pest** D) ** A and B** E)** All of the above **Answer:** C) Considers the biology of the target pest **Explanation:** IPM is a comprehensive approach that considers pest biology, ecology, and behavior to develop sustainable control strategies. It integrates multiple control methods (biologi