Bivalvia MCQs December 4, 2025September 30, 2024 by u930973931_answers 30 min Score: 0 Attempted: 0/30 Subscribe 1. What is the primary feature that distinguishes bivalves from other mollusks? (A) Presence of a shell (B) Radula (C) Two-part shell (valves) (D) Tentacles 2. Which of the following is a common habitat for bivalves? (A) All of the above (B) Freshwater lakes (C) Estuaries (D) Marine environments 3. Bivalves primarily feed through which mechanism? (A) Filter feeding (B) Grazing (C) Predation (D) Parasitism 4. The two shells of a bivalve are connected by a structure called: (A) Ligament (B) Hinge (C) Adductor muscle (D) Mantle 5. Which bivalve is commonly known for producing pearls? (A) Oyster (B) Clam (C) Scallop (D) Mussel 6. The main method of locomotion in bivalves is: (A) Swimming (B) Crawling (C) Burrowing (D) Jet propulsion 7. Which part of the bivalve is responsible for secreting the shell? (A) Foot (B) Mantle (C) Gills (D) Visceral mass 8. What type of circulatory system do bivalves have? (A) Simple diffusion (B) Closed circulatory system (C) No circulatory system (D) Open circulatory system 9. Which of the following is NOT a typical feature of bivalves? (A) Two shells (B) Gills (C) Tentacles (D) Foot 10. Bivalves are primarily: (A) Herbivores (B) Carnivores (C) Detritivores (D) Omnivores 11. What is the role of the siphons in bivalves? (A) Movement (B) Feeding and respiration (C) Reproduction (D) Protection 12. Which of the following bivalves is known for its ability to swim? (A) Clam (B) Scallop (C) Oyster (D) Mussel 13. Which structure in bivalves helps in respiration? (A) Gills (B) Foot (C) Mantle cavity (D) Siphons 14. What is the primary method of reproduction in most bivalves? (A) Asexual reproduction (B) Sexual reproduction (C) Budding (D) Fragmentation 15. Bivalves can be found in which of the following types of environments? (A) Intertidal zones (B) All of the above (C) Freshwater rivers (D) Deep ocean 16. Which of the following is a key ecological role of bivalves? (A) Habitat formation (B) Water filtration (C) All of the above (D) Nutrient cycling 17. How do bivalves contribute to their ecosystems? (A) By acting as predators (B) By filtering water and improving water quality (C) B and C only (D) By providing food for other organisms 18. Which bivalve is commonly used for human consumption? (A) Pearl oyster (B) Zebra mussel (C) Sea cucumber (D) Clam 19. What happens to bivalves when they are exposed to low oxygen levels? (A) They may die or become inactive (B) They migrate (C) They thrive (D) They reproduce 20. The largest bivalve species is: (A) Tridacna gigas (Giant clam) (B) Mytilus edulis (Blue mussel) (C) Pinctada margaritifera (Black-lipped oyster) (D) Crassostrea virginica (Eastern oyster) 21. Which part of the bivalve's body contains the vital organs? (A) Visceral mass (B) Mantle (C) Foot (D) Shell 22. Which of the following is a common way to harvest bivalves? (A) All of the above (B) Trawling (C) Hand gathering (D) Dredging 23. What is the primary purpose of the adductor muscles in bivalves? (A) To aid in locomotion (B) To respire (C) To filter food (D) To open and close the shell 24. Bivalves have a simple nervous system characterized by: (A) A centralized brain (B) Complex sense organs (C) A series of ganglia (D) No nervous system 25. What is the main threat to bivalve populations worldwide? (A) Habitat loss (B) Overharvesting (C) Pollution (D) All of the above 26. The "foot" of a bivalve is primarily used for: (A) Attachment to substrates (B) Locomotion (C) All of the above (D) Digging into sediment 27. Which bivalve is known for its unique ability to produce byssal threads for attachment? (A) Scallop (B) Clam (C) Oyster (D) Mussel 28. Which bivalve group is characterized by having siphons that extend into the water column? (A) All of the above (B) Attached bivalves (C) Free-living bivalves (D) Burrowing bivalves 29. What is the significance of the byssus in mussels? (A) Feeding (B) Respiration (C) Attachment (D) Protection 30. The term "scallops" refers to which of the following characteristics? (A) They have a smooth, flat shell (B) They do not have a shell (C) They are primarily found in freshwater (D) They can swim by clapping their shells together