Ophiuroidea MCQs January 8, 2026September 28, 2024 by u930973931_answers 30 min Score: 0 Attempted: 0/30 Subscribe 1. What is the common name for members of the class Ophiuroidea? (A) Sea urchins (B) Starfish (C) Sea cucumbers (D) Brittle stars 2. Which of the following best describes the body structure of Ophiuroidea? (A) A rigid shell with spines (B) A central disc with long, slender arms (C) A soft, elongated body (D) A star-shaped body with thick arms 3. What is the primary mode of locomotion for Ophiuroidea? (A) Swimming (B) Jet propulsion (C) Crawling using their arms (D) Burrowing 4. How do Ophiuroidea typically feed? (A) By filter feeding (B) By scavenging and predation (C) Through photosynthesis (D) By absorbing nutrients from the water 5. What type of skeleton do Ophiuroidea have? (A) Endoskeleton (B) Exoskeleton (C) Hydrostatic skeleton (D) Cartilaginous skeleton 6. What is the function of the madreporite in Ophiuroidea? (A) It aids in digestion. (B) It assists in reproduction. (C) It regulates water pressure in the water vascular system. (D) It serves as a sensory organ. 7. What do Ophiuroidea use for gas exchange? (A) Surface diffusion through the body wall (B) Skin gills (C) Specialized lungs (D) Gills 8. Which sensory structure is commonly found on Ophiuroidea? (A) Eyespots (B) Antennae (C) Tentacles (D) Sensory tube feet 9. How do Ophiuroidea typically reproduce? (A) Asexual budding (B) Internal fertilization (C) External fertilization (D) Parthenogenesis 10. Which of the following is a common habitat for Ophiuroidea? (A) Freshwater (B) Deep ocean floors (C) Shallow coastal waters (D) Terrestrial environments 11. What is the role of tube feet in Ophiuroidea? (A) Locomotion and feeding (B) Respiration (C) Digestion (D) Sensory reception 12. What is a notable defense mechanism of Ophiuroidea? (A) Ejection of stomach contents (B) Camouflage (C) Autotomy (self-amputation of arms) (D) Production of toxins 13. Which type of symmetry do Ophiuroidea exhibit? (A) Bilateral symmetry (B) Radial symmetry (C) Asymmetry (D) Pentaradial symmetry 14. What type of circulatory system do Ophiuroidea have? (A) Open circulatory system (B) Water vascular system (C) Closed circulatory system (D) No circulatory system 15. Which of the following describes the feeding process of Ophiuroidea? (A) They digest food externally before ingestion. (B) They ingest food whole. (C) They filter food from the water. (D) They consume prey using their tube feet. 16. How do Ophiuroidea contribute to marine ecosystems? (A) They act as primary producers. (B) They are key predators in their environment. (C) They help recycle nutrients in marine ecosystems. (D) All of the above 17. What is the primary diet of most Ophiuroidea species? (A) Algae (B) Coral (C) Detritus and small invertebrates (D) Plankton 18. Which Ophiuroidea species is known for its unique coloration? (A) Crown-of-thorns starfish (B) Brittle star (C) Sea lily (D) Basket star 19. What is a key characteristic of the arms of Ophiuroidea? (A) They are fleshy and broad. (B) They are slender and flexible. (C) They are thick and muscular. (D) They are short and rigid. 20. How do Ophiuroidea typically escape predators? (A) By swimming quickly (B) By releasing toxins (C) By hiding in crevices (D) By regenerating lost arms 21. Which of the following describes the habitat range of Ophiuroidea? (A) Only in shallow waters (B) Only in deep ocean environments (C) Found in a variety of marine habitats from shallow to deep waters (D) Only in freshwater environments 22. Which of the following adaptations do Ophiuroidea have for feeding? (A) Filter feeding structures (B) Specialized jaws (C) A muscular stomach for grinding food (D) Long tube feet for grasping prey 23. What is the ecological role of Ophiuroidea in the benthic community? (A) They are primary producers. (B) They provide shelter for smaller organisms. (C) They are scavengers and predators, helping to control prey populations. (D) They compete with fish for food resources. 24. What is the typical lifespan of an Ophiuroidea? (A) Less than one year (B) 5 to 10 years (C) 1 to 5 years (D) Over 20 years 25. What environmental factors can affect the distribution of Ophiuroidea? (A) All of the above (B) Salinity (C) Depth (D) Temperature 26. What is the process called when Ophiuroidea lose an arm to escape a predator? (A) Evisceration (B) Regeneration (C) Autotomy (D) Fragmentation 27. How do Ophiuroidea detect food in their environment? (A) Using eyespots on their arms (B) Through chemical cues in the water (C) Using their tube feet (D) All of the above 28. What type of feeders are Ophiuroidea classified as? (A) Herbivores (B) Omnivores (C) Carnivores (D) Detritivores 29. Which of the following is a characteristic feature of Ophiuroidea? (A) Thick, muscular arms (B) Long, slender, and flexible arms (C) Highly branched arms (D) A central disc with no distinct arms 30. What is the significance of Ophiuroidea in marine food webs? (A) They are primary producers. (B) They have no significant role. (C) They serve as a food source for larger predators. (D) They are invasive species.