Aquatic Biology MCQs with Answers

Which term describes the process by which aquatic organisms move towards or away from light?

What is the name of the bacteria that live symbiotically in the roots of leguminous plants and fix nitrogen?

What is the name of the physical structure that separates the marine environment into different zones based on depth?

Which type of fish can live in both freshwater and saltwater environments?

What is the term for the process by which aquatic organisms take in dissolved oxygen from water?

What is the term for organisms that live at the bottom of oceans, lakes, or rivers?

Which group of organisms play a crucial role in the carbon cycle by fixing carbon dioxide into organic compounds?

What is the term for the vertical movement of water driven by differences in temperature and salinity?

Which term describes the process by which excess nutrients in aquatic ecosystems lead to oxygen depletion?

Which term describes the gradual transition from one type of aquatic ecosystem to another?

What is the term for the upper layer of water in an aquatic ecosystem where sunlight penetrates?

What is the name of the relationship between a fungus and a photosynthetic partner in aquatic environments?

What is the name of the symbiotic relationship between algae and fungi in aquatic environments?

Which term describes the process by which dissolved substances move across a semipermeable membrane?

What is the term for the protective external skeleton of arthropods found in aquatic environments?

Which type of aquatic organism is known for its ability to filter and clean water in aquatic ecosystems?

Which term describes the ability of aquatic organisms to maintain internal salt concentrations different from their environment?

What is the term for the microscopic animals that live in freshwater and marine environments, feeding on plankton?

What is the name of the specialized respiratory organ in fish that extracts oxygen from water?

Which type of fish migrates from freshwater rivers to the ocean to reproduce?

Which group of organisms are microscopic animals that drift or swim near the surface of aquatic environments?

What is the term for the movement of water up from the roots of plants in aquatic environments?

Which term describes the process by which aquatic organisms remove particles from the water column?

Which organism is known as the "sea walnut" and belongs to the group of comb jellies?

Which process involves the conversion of nitrogen gas into ammonia by aquatic bacteria?

What is the name of the biogeochemical cycle that describes the movement of water on Earth?

What is the name of the ecological region where freshwater rivers meet saltwater oceans?

Which term describes the movement of marine organisms up and down in the water column?

What is the name of the process by which aquatic organisms convert ammonium into nitrites and then into nitrates?

Which type of marine organism is known for its ability to produce bioluminescent light?

What is the name of the symbiotic relationship between algae and coral polyps in coral reefs?

What is the name of the aquatic ecosystem characterized by high biodiversity and productivity due to nutrient-rich runoff?

What is the term for the process by which dissolved nutrients like nitrogen and phosphorus accumulate in bodies of water?

Which type of algae are known as microscopic floating plants found in aquatic ecosystems?

Which term describes the process by which aquatic organisms release waste products into their environment?

Which term describes the adaptation of marine organisms to survive in environments with low oxygen levels?

What is the name of the process by which aquatic organisms release excess salts from their bodies?

What is the name of the aquatic ecosystems with high levels of salt concentration?

Which aquatic organisms have a backbone and can regulate their body temperature internally?

What is the term for the process by which aquatic plants and algae produce oxygen during photosynthesis?