Plectida MCQs December 4, 2025September 30, 2024 by u930973931_answers 30 min Score: 0 Attempted: 0/30 Subscribe 1. What is the primary habitat of Plectida nematodes? (A) Terrestrial soil (B) Marine environments (C) Freshwater (D) Airborne 2. Plectida nematodes are primarily characterized by their: (A) Complex life cycles (B) Thick cuticle (C) Reduced body size (D) Elongated bodies 3. Which of the following is a notable feature of Plectida nematodes? (A) Presence of a stylet (B) Segmented body (C) Lack of amphids (D) Large pharyngeal bulb 4. The diet of Plectida nematodes typically includes: (A) Algae (B) Fungi and bacteria (C) Larger invertebrates (D) Plant roots 5. Which structure is often used for sensory perception in Plectida nematodes? (A) Claspers (B) Amphids (C) Setae (D) Pharyngeal bulb 6. Plectida nematodes are known to have a body shape that is: (A) Cylindrical (B) Flattened (C) Irregular (D) Disk-shaped 7. Which of the following genera is classified under the order Plectida? (A) Plectus (B) Caenorhabditis (C) Rhabditis (D) Heterodera 8. What is the significance of Plectida nematodes in soil ecosystems? (A) They are top predators (B) They filter sediments (C) They are parasitic on plants (D) They contribute to nutrient cycling 9. The reproduction of Plectida nematodes is typically: (A) Asexual (B) Parthenogenetic (C) Sexual (D) Budding 10. Which feature of Plectida nematodes aids in their identification? (A) Smooth cuticle (B) Coloration (C) Presence of annulations (D) Size 11. Plectida nematodes can be classified as: (A) Ectoparasites (B) Endoparasites (C) Symbiotic (D) Free-living 12. Which of the following is NOT a characteristic of Plectida nematodes? (A) Segmented body (B) Thick cuticle (C) Setae on the body (D) Elongated bodies 13. Which of the following is a reproductive strategy of Plectida nematodes? (A) Synchronous spawning (B) Asexual budding (C) External fertilization (D) Internal fertilization 14. Plectida nematodes are important in which ecological role? (A) Herbivores (B) Predators (C) Decomposers (D) Parasitic hosts 15. The life cycle of Plectida nematodes typically includes: (A) Multiple larval stages (B) Direct development without a larval stage (C) Complex interactions with host organisms (D) Parthenogenetic reproduction 16. Which of the following statements about Plectida nematodes is true? (A) They have a significant role in soil health (B) They are primarily aquatic (C) They have a simple body structure (D) They are parasites of humans 17. What is the typical size range for Plectida nematodes? (A) Over 20 mm (B) 1 to 10 mm (C) 10 to 20 mm (D) 0.1 to 1 mm 18. Which of the following adaptations helps Plectida nematodes in their environment? (A) Thick cuticle for protection (B) Ability to swim (C) Coloration for camouflage (D) High metabolic rate 19. The amphids in Plectida nematodes are primarily used for: (A) Sensory functions (B) Locomotion (C) Feeding (D) Reproduction 20. Which of the following features is characteristic of the Plectida life cycle? (A) Parthenogenetic reproduction (B) Direct development without a larval stage (C) Complex interactions with host organisms (D) Multiple larval stages 21. Plectida nematodes are most commonly studied in relation to: (A) Soil health (B) Aquaculture (C) Marine ecology (D) Parasitology 22. Which of the following best describes the ecological role of Plectida in soil ecosystems? (A) They are important decomposers (B) They are top predators (C) They are primary producers (D) They are symbionts of plants 23. The ability of Plectida nematodes to survive in harsh environments is attributed to their: (A) High reproductive rate (B) Thick cuticle (C) Small size (D) Symbiotic relationships 24. Which of the following adaptations aids in the feeding of Plectida nematodes? (A) Large mouth (B) Highly developed eyes (C) Siphoning mechanism (D) Presence of a stylet 25. Plectida nematodes are significant in soil health because they: (A) Compete with plants for nutrients (B) Filter sediments (C) Break down organic matter (D) Prey on larger nematodes 26. Which of the following is a common method for studying Plectida nematodes? (A) Microscopy (B) Genetic sequencing (C) All of the above (D) Environmental sampling 27. The primary mode of locomotion for Plectida nematodes is: (A) Swimming (B) Crawling (C) Floating (D) Burrowing 28. Which of the following factors influences the distribution of Plectida nematodes? (A) Temperature (B) Soil moisture (C) Organic matter availability (D) All of the above 29. The presence of Plectida nematodes in soil is often an indicator of: (A) High salinity (B) Healthy ecosystem (C) Pollution levels (D) Poor soil structure 30. Which of the following statements about Plectida nematodes is true? (A) They have a short life cycle (B) They play a role in nutrient cycling (C) They are primarily herbivorous (D) They are exclusively aquatic