Merostomata MCQs December 4, 2025September 28, 2024 by u930973931_answers 29 min Score: 0 Attempted: 0/29 Subscribe 1. Merostomata is commonly known as: (A) Crabs (B) Horseshoe crabs (C) Spiders (D) Shrimp 2. What type of body structure do horseshoe crabs possess? (A) Soft-bodied (B) Segmented (C) Jelly-like (D) Hard exoskeleton 3. Horseshoe crabs primarily belong to which class? (A) Crustacea (B) Arachnida (C) Merostomata (D) Insecta 4. The primary habitat of horseshoe crabs is: (A) Freshwater lakes (B) Coastal marine waters (C) Terrestrial environments (D) High mountains 5. Horseshoe crabs have how many pairs of legs? (A) 10 (B) 5 (C) 4 (D) 6 6. Which of the following structures is unique to horseshoe crabs? (A) Chelipeds (B) Gills (C) Telson (D) Antennae 7. What is the main diet of horseshoe crabs? (A) Omnivorous (B) Carnivorous (C) Detritivorous (D) Herbivorous 8. Horseshoe crabs are most closely related to which group? (A) Arachnids (B) Insects (C) Mollusks (D) Crustaceans 9. The blood of horseshoe crabs is notable for its high content of: (A) Hemoglobin (B) Hemocyanin (C) Chlorophyll (D) Collagen 10. Which of the following is TRUE about the reproductive habits of horseshoe crabs? (A) They lay eggs in the sand (B) They are ovoviviparous (C) They reproduce asexually (D) They give live birth 11. The larval stage of horseshoe crabs is called: (A) Nauplius (B) Zoea (C) Trinomial (D) Trilobite 12. Horseshoe crabs are most active during which time of day? (A) Morning (B) Afternoon (C) Night (D) They are diurnal 13. Which of the following is NOT a feature of horseshoe crabs? (A) Compound eyes (B) Chelicerae (C) Fangs (D) Segmented body 14. The primary function of the horseshoe crab's telson is: (A) Locomotion (B) Navigation (C) Digestion (D) Defense 15. Which of the following best describes the respiratory system of horseshoe crabs? (A) Gills (B) Book gills (C) Lungs (D) Spiracles 16. What role do horseshoe crabs play in the marine ecosystem? (A) Prey for other animals (B) Predators (C) Decomposers (D) Pollinators 17. Horseshoe crabs are known for their long history, dating back to: (A) The Jurassic period (B) The Cambrian period (C) The Ordovician period (D) The Triassic period 18. The primary function of the horseshoe crab's exoskeleton is to: (A) Facilitate movement (B) Protect internal organs (C) Aid in respiration (D) Provide buoyancy 19. Horseshoe crabs can often be found in what kind of waters? (A) Deep oceanic (B) High-altitude lakes (C) Freshwater rivers (D) Shallow coastal waters 20. Which of the following adaptations helps horseshoe crabs to move through sediment? (A) Strong legs (B) Flat body shape (C) Long telson (D) Flexible exoskeleton 21. Which of the following is a characteristic of horseshoe crab reproduction? (A) Parasitism (B) Internal fertilization (C) Asexual reproduction (D) External fertilization 22. Horseshoe crabs primarily use their pedipalps for: (A) Swimming (B) Defense (C) Grasping food (D) Walking 23. What is the scientific significance of horseshoe crab blood? (A) All of the above (B) It contains a substance that detects bacterial contamination (C) It is used in vaccines (D) It is used for scientific research 24. Which of the following is a threat to horseshoe crab populations? (A) Habitat loss (B) Overfishing (C) Pollution (D) All of the above 25. What type of symmetry do horseshoe crabs exhibit? (A) None of the above (B) Radial symmetry (C) Asymmetry (D) Bilateral symmetry 26. Which structure helps horseshoe crabs to sense their environment? (A) Compound eyes (B) Simple eyes (C) Antennae (D) Spiracles 27. Horseshoe crabs are known for their ability to: (A) Change color (B) Regenerate lost limbs (C) Produce silk (D) Swim rapidly 28. What is the primary purpose of the horseshoe crab's carapace? (A) Aid in swimming (B) Facilitate respiration (C) Help with digestion (D) Protect the body 29. Horseshoe crabs are often used in: (A) Agriculture (B) Medical research (C) Aquaculture (D) All of the above