Marine Ecology of Animal mcqs January 8, 2026April 9, 2024 by u930973931_answers 50 min Score: 0 Attempted: 0/50 Subscribe 1. What is the primary factor that determines the distribution of marine organisms? (A) Temperature (B) Salinity (C) pH (D) Depth 2. Which of the following is NOT a characteristic of marine ecosystems? (A) Presence of sunlight (B) High salinity (C) Low oxygen levels (D) Abundance of dissolved nutrients 3. Which zone of the ocean experiences the highest levels of sunlight penetration? (A) Epipelagic zone (B) Mesopelagic zone (C) Bathypelagic zone (D) Abyssopelagic zone 4. Organisms living in the aphotic zone of the ocean primarily rely on: (A) Photosynthesis (B) Chemosynthesis (C) Predation (D) Decomposition 5. Which of the following is NOT a common adaptation of marine animals for living in the deep sea? (A) Bioluminescence (B) Reduced metabolism (C) Large eyes (D) Enhanced mobility 6. Which marine ecosystem is characterized by the presence of large colonies of corals? (A) Kelp forests (B) Coral reefs (C) Estuaries (D) Mangrove forests 7. What is the main limiting factor for the distribution of coral reefs? (A) Temperature (B) Salinity (C) Sunlight (D) Nutrient availability 8. Which of the following is a keystone species in coral reef ecosystems? (A) Clownfish (B) Sea urchin (C) Parrotfish (D) Octopus 9. Which of the following statements about mangrove forests is true? (A) They are found primarily in temperate regions. (B) They cannot tolerate high levels of salinity. (C) They provide important nursery habitats for many marine species. (D) They are devoid of any animal life. 10. Which marine ecosystem is characterized by dense stands of macroalgae? (A) Coral reefs (B) Mangrove forests (C) Kelp forests (D) Seagrass beds 11. Which of the following is NOT a factor contributing to the decline of global fish stocks? (A) Overfishing (B) Habitat destruction (C) Ocean acidification (D) Marine pollution 12. What is the term used to describe the migration of organisms from one part of the ocean to another? (A) Estivation (B) Hibernation (C) Diapause (D) Dispersal 13. Which of the following is an example of a pelagic organism? (A) Barnacle (B) Starfish (C) Jellyfish (D) Sea anemone 14. What type of organism is found at the base of most marine food webs? (A) Phytoplankton (B) Zooplankton (C) Seagrasses (D) Sea urchins 15. Which of the following is NOT a characteristic of a benthic organism? (A) Sessile lifestyle (B) Ability to swim against currents (C) Attachment to the ocean floor (D) Adaptations for filter feeding 16. What is the primary function of the lateral line system in fishes? (A) Detecting changes in water temperature (B) Sensing water pressure (C) Detecting movement and vibration in the water (D) Navigating in murky waters 17. Which of the following is an example of a demersal fish? (A) Tuna (B) Sardine (C) Cod (D) Salmon 18. What is the term used to describe the ability of certain marine organisms to change their coloration or pattern for camouflage? (A) Bioluminescence (B) Countershading (C) Disruptive coloration (D) Chromatophores 19. Which of the following marine mammals is known for its ability to echolocate? (A) Walrus (B) Manatee (C) Dolphin (D) Dugong 20. What is the primary function of the swim bladder in bony fishes? (A) Buoyancy control (B) Gas exchange (C) Excretion (D) Sensory perception 21. Which of the following is NOT a characteristic of marine reptiles? (A) Oviparous reproduction (B) Internal fertilization (C) Ability to regulate body temperature (D) Gills for respiration 22. Which of the following is a type of marine turtle? (A) Anaconda (B) Komodo dragon (C) Green turtle (D) Alligator 23. What is the main reason for the decline in global populations of sea turtles? (A) Climate change (B) Pollution (C) Overfishing (D) Habitat loss 24. What is the primary prey of the great white shark? (A) Krill (B) Seals (C) Tuna (D) Squid 25. Which of the following is NOT a type of symbiotic relationship found in marine ecosystems? (A) Parasitism (B) Commensalism (C) Mutualism (D) Predation 26. What is the term used to describe the process by which marine organisms remove dissolved nutrients from the water? (A) Denitrification (B) Nitrification (C) Nitrogen fixation (D) Assimilation 27. Which of the following is a type of filter-feeding organism commonly found in marine ecosystems? (A) Sea cucumber (B) Sea anemone (C) Sponge (D) Sea urchin 28. Which of the following is NOT a characteristic of marine birds? (A) Ability to dive for extended periods (B) Waterproof feathers (C) Oviparous reproduction (D) Warm-blooded metabolism 29. Which marine bird is known for its long migrations between breeding and feeding grounds? (A) Albatross (B) Penguin (C) Cormorant (D) Gull 30. What is the primary function of the gills in marine fishes? (A) Buoyancy control (B) Gas exchange (C) Excretion (D) Sensory perception 31. Which of the following is NOT a type of marine invertebrate? (A) Octopus (B) Coral (C) Crab (D) Mackerel 32. What is the term used to describe the movement of water driven by differences in temperature and salinity? (A) Erosion (B) Turbidity (C) Thermohaline circulation (D) Upwelling 33. Which of the following is NOT a characteristic of marine worms? (A) Bilateral symmetry (B) Soft bodies (C) Exoskeletons (D) Segmented bodies 34. What is the main source of energy for deep-sea hydrothermal vent communities? (A) Sunlight (B) Chemosynthesis (C) Photosynthesis (D) Decomposition 35. Which of the following marine invertebrates is capable of regeneration? (A) Sea urchin (B) Jellyfish (C) Sea anemone (D) Octopus 36. What is the primary function of the mantle in mollusks? (A) Protection (B) Sensory perception (C) Gas exchange (D) Shell formation 37. Which of the following marine organisms is NOT a member of the Cnidaria phylum? (A) Jellyfish (B) Coral (C) Sea anemone (D) Sponge 38. What is the term used to describe the process by which marine organisms release carbon dioxide into the atmosphere? (A) Photosynthesis (B) Respiration (C) Decomposition (D) Denitrification 39. Which of the following is NOT a characteristic of marine crustaceans? (A) Jointed appendages (B) Exoskeleton made of chitin (C) Radial symmetry (D) Segmented bodies 40. What is the primary function of the ampullae of Lorenzini in sharks? (A) Gas exchange (B) Sensory perception (C) Buoyancy control (D) Reproduction 41. Which of the following is NOT a threat to coral reefs? (A) Ocean acidification (B) Overfishing (C) Climate change (D) Seagrass expansion 42. What is the main reason for the decline in global populations of sharks? (A) Climate change (B) Pollution (C) Overfishing (D) Habitat loss 43. Which of the following is NOT a characteristic of marine arthropods? (A) Exoskeleton made of chitin (B) Jointed appendages (C) Radial symmetry (D) Segmented bodies 44. What is the main source of energy for organisms living in the aphotic zone of the ocean? (A) Sunlight (B) Chemosynthesis (C) Photosynthesis (D) Decomposition 45. Which of the following marine organisms is known for its ability to change sex during its lifetime? (A) Clownfish (B) Parrotfish (C) Sea anemone (D) Moray eel 46. What is the term used to describe the process by which marine organisms convert nitrogen gas into a usable form? (A) Denitrification (B) Nitrification (C) Nitrogen fixation (D) Assimilation 47. Which of the following is NOT a characteristic of marine mammals? (A) Warm-blooded metabolism (B) Waterproof fur or blubber (C) Oviparous reproduction (D) Mammary glands for milk production 48. What is the primary function of the lateral line system in fishes? (A) Detecting changes in water temperature (B) Sensing water pressure (C) Detecting movement and vibration in the water (D) Navigating in murky waters 49. Which of the following is a type of marine reptile? (A) Dolphin (B) Turtle (C) Seal (D) Penguin 50. What is the main reason for the decline in global populations of sea turtles? (A) Climate change (B) Pollution (C) Overfishing (D) Habitat loss