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2.5 Nemathelminthes — Test 1
Q1. A pseudocoelom is a body cavity that:✓ Is not fully lined by mesodermal peritoneum
Q2. Eutely, a feature of nematodes, refers to the:✓ Constant number of body cells in adults
Q3. Filariasis (which can cause elephantiasis) is caused by the nematode:✓ Wuchereria bancrofti
Q4. In Ascaris, the sexes are:✓ Separate (dioecious), with males smaller than females
Q5. The roundworm that commonly infects the human intestine and is acquired by eating contaminated food is:✓ Ascaris lumbricoides
Q6. Nematodes are covered by a tough external layer called the:✓ Cuticle
Q7. Which one of the following is NOT a pseudocoelomate?✓ Echinococcus (a tapeworm)
Q8. The pinworm that causes itching around the anus, especially in children, is:✓ Enterobius vermicularis
Q9. Nematodes possess only longitudinal muscles, so they move with a characteristic:✓ Whip-like or thrashing motion
Q10. Hookworm (Ancylostoma) infection in humans typically causes:✓ Anaemia from blood loss in the intestine
Q11. Nematodes have a body cavity that is a:✓ Pseudocoel (persistent blastocoel)
Q12. Trichinella spiralis is acquired by humans through:✓ Eating undercooked pork containing encysted larvae
Q13. Nematodes have a complete digestive system, which means they have:✓ Both a mouth and an anus
Q14. The guinea worm (Dracunculus medinensis) is transmitted to humans by:✓ Drinking water containing infected copepods (Cyclops)
Q15. Nematodes grow by periodically shedding their cuticle, a process called:✓ Moulting (ecdysis)
Q16. The phylum Nemathelminthes (Aschelminthes) is best characterised as:✓ Unsegmented pseudocoelomate worms with a complete gut
Q17. In Ascaris, the body-cavity fluid is under pressure and serves as a:✓ Hydrostatic skeleton aiding movement
Q18. Most parasitic nematodes have a life cycle that involves:✓ Production of large numbers of resistant eggs
Q19. Caenorhabditis elegans, a model organism, is valued in research because it has a:✓ Fixed and fully mapped cell lineage
Q20. Elephantiasis, with gross swelling of the limbs, results from:✓ Blockage of lymph vessels by filarial worms