Medical Entomology & Parasitology CAT — OmpathStudy

--- ⚠️ Answers added by AI : some answers in this document were generated by AI from general medical knowledge, not the original exam paper. Verify against your course material before relying on them for the exam. Question 1 Fish are second intermediate hosts of? A. Echinostoma ilocaanum B. Faciola hepatica C. Fasciolopsis buski D. Hymenolepis nana E. Clorchis sinesis Answer: E. Clonorchis sinensis Explanation: Fish serve as the second intermediate host for Clonorchis sinensis (Chinese liver fluke); the snail is the first intermediate host. --- Question 2 Which of the following secretes defensive secretions to cause irritation on human skin? A. Millipedes B. Centipedes C. Necator americanus D. Enterobius vermicularis E. All of the above Answer: A. Millipedes Explanation: Millipedes release chemical defensive secretions causing skin irritation on contact; centipedes envenomate by biting instead. --- Question 3 Holometabolous insects have? A. 2 life stages B. 3 life stages C. 4 life stages D. 5 life stages E. 1 life stage Answer: C. 4 life stages Explanation: Complete metamorphosis = egg, larva, pupa, adult. --- Question 4 Which of the following transmits parasites for river blindness? A. Culex species B. Chrysops species C. Simulium species D. Toxorhynchintinae species E. All of the above Answer: C. Simulium species Explanation: Simulium (blackfly) transmits Onchocerca volvulus , causing river blindness. --- Question 5 Which insecticide targets GABA in its action? A. DDT B. DEET C. Permethrin D. Bendiocarb E. Malathion Answer: No listed option is correct. Explanation: DDT and permethrin act primarily on voltage-gated sodium channels. Cyclodiene insecticides such as aldrin/dieldrin and phenylpyrazoles such as fipronil are the classic GABA-gated chloride-channel antagonists. This source item is flawed. --- Question 6 Presence of triatomine bugs could predispose the population to? A. Sleeping sickness B. Leishmaniasis C. Malaria D. Chagas disease E. River blindness Answer: D. Chagas disease Explanation: Triatomine (kissing/reduviid) bugs transmit Trypanosoma cruzi . --- Question 7 People living in forested areas like Arabuko Sokoke are at risk of? A. Sleeping sickness B. Leishmaniasis C. Malaria D. Encephalitis E. River blindness Answer: A. Sleeping sickness Explanation: Arabuko Sokoke forest is a known tsetse fly habitat, putting residents at risk for African trypanosomiasis. --- Question 8 Which of the following insects are commonly found in Latin America? A. Glossina species B. Triatomine bugs C. Cimex species D. Chrysops species E. Steam bugs Answer: B. Triatomine bugs Explanation: Triatomine bugs are native to Central/South America; Glossina (tsetse fly) is exclusively African. --- Question 9 Pruritis can be best diagnosed for? A. Sarcoptes scabiei B. Leptotrombidium species C. Blattella species D. Pediculus species E. Pthirus species Answer: A. Sarcoptes scabiei Explanation: Intense itching (pruritis) is diagnostic for scabies, caused by this mite. --- Question 10 If you found lice eggs (nits) in someone's clothing, what species would they most likely be from? A. Crab lice B. Pediculus humanus C. Pediculus capitis D. Pthirus species E. All of the above / Hog lice Answer: B. Pediculus humanus Explanation: The body louse lays its eggs in clothing seams, unlike head or crab lice. --- Question 11 Which of the following is odd one out in terms of transmission? A. Vibrio cholera B. Entamoeba histolytica C. Rotavirus D. Thelazia species E. None of the above Answer: D. Thelazia species Explanation: The other three are faecal-oral; Thelazia (eyeworm) is transmitted by fruit flies feeding on eye secretions. --- Question 12 Which one of the following is larviparous? A. Phlebotomus species B. Lutzomyia species C. Triatomine bugs D. Glossina gambiense E. Dermacentos species Answer: D. Glossina gambiense Explanation: Tsetse flies ( Glossina ) are adenotrophically viviparous: the female nourishes one larva internally and deposits a mature larva. Lutzomyia sandflies lay eggs and are not larviparous. --- Question 13 Argasid ticks have? A. One host B. Two hosts C. Three hosts D. Multiple hosts E. Four hosts Answer: D. Multiple hosts Explanation: Soft ticks feed briefly and repeatedly across multiple hosts. --- Question 14 Ixodid ticks have nymphal stages. A. One B. Two C. Three D. Four E. Multiple Answer: A. One Explanation: Hard ticks have only one nymphal stage in their 3-host life cycle. --- Question 15 Traps for Aedes mosquitoes are composed of? A. Black and white colors B. Black and blue colors C. White and blue colors D. White only E. Black only Answer: B. Black and blue colors --- Question 16 Traps for Glossina species are composed of? A. Black and white colors B. Black and blue colors C. White and blue colors D. White only E. Black only Answer: B. Black and blue colors Explanation: Same trap coloring attracts both Aedes and tsetse flies. --- Question 17 Black water disease is due to presence of in the environment.