Aquatic Biology MCQs with Answers

Aquatic Biology MCQs are very important test and often asked by various testing services and competitive exams around the world. Here you will find all the Important Aquatic Biology MCQs for Preparation.

The student can clear their concepts for Aquatic Biology online quiz by attempting it. Doing MCQs based Aquatic Biology will help you to check your understanding and identify areas of improvement.

Aquatic Biology Online MCQs with Answers

Which of the following is a characteristic of freshwater ecosystems?
a) High salinity
b) Abundance of marine organisms
c) Low mineral content
d) High oxygen levels

Answer
c) Low mineral content

Which of the following is an example of a pelagic zone in the ocean?
a) Coral reef
b) Rocky shore
c) Open ocean
d) Mangrove swamp

Answer
c) Open ocean

The process by which an organism maintains a stable internal environment despite changes in the external environment is called:
a) Adaptation
b) Homeostasis
c) Osmoregulation
d) Acclimation

Answer
b) Homeostasis

Which of the following is a primary producer in aquatic ecosystems?
a) Fish
b) Phytoplankton
c) Zooplankton
d) Jellyfish

Answer
b) Phytoplankton

What is the term for the movement of water from a region of higher concentration of solutes to a region of lower concentration through a semi-permeable membrane?
a) Osmosis
b) Diffusion
c) Active transport
d) Filtration

Answer
a) Osmosis

Which of the following is a characteristic of estuaries?
a) High levels of salinity
b) Limited biodiversity
c) Stable water temperatures
d) Mixing of fresh and saltwater

Answer
d) Mixing of fresh and saltwater

The open ocean is divided into different zones based on:
a) Temperature
b) Salinity
c) Depth
d) Currents

Answer
c) Depth

Which of the following is an example of a benthic organism?
a) Sea turtle
b) Tuna fish
c) Phytoplankton
d) Sea anemone

Answer
d) Sea anemone

The Great Barrier Reef is an example of which type of ecosystem?
a) Freshwater lake
b) Salt marsh
c) Coral reef
d) Kelp forest

Answer
c) Coral reef

Which of the following is a key factor that influences the distribution of organisms in aquatic ecosystems?
a) Oxygen levels
b) Soil pH
c) Wind direction
d) Human activities

Answer
a) Oxygen levels

What is the term for the process by which aquatic organisms extract dissolved oxygen from the surrounding water?
a) Photosynthesis
b) Respiration
c) Diffusion
d) Osmosis

Answer
b) Respiration

Which of the following is a characteristic of wetlands?
a) High levels of salinity
b) Limited vegetation
c) Waterlogged soils
d) Deep-water habitats

Answer
c) Waterlogged soils

What is the term for the process by which aquatic organisms convert inorganic carbon dioxide into organic compounds?
a) Respiration
b) Decomposition
c) Photosynthesis
d) Osmosis

Answer
c) Photosynthesis

Which of the following is a characteristic of mangrove ecosystems?
a) High levels of salinity
b) Absence of vegetation
c) Oxygen-rich soils
d) Protection against tidal waves and erosion

Answer
d) Protection against tidal waves and erosion

Which of the following is a primary consumer in aquatic ecosystems?
a) Zooplankton
b) Phytoplankton
c) Sharks
d) Seaweed

Answer
a) Zooplankton

What is the term for the process by which excess nutrients, such as nitrogen and phosphorus, enter aquatic ecosystems and cause excessive growth of algae?
a) Eutrophication
b) Biomagnification
c) Acidification
d) Desalination

Answer
a) Eutrophication

Which of the following is a characteristic of coral reefs?
a) Low biodiversity
b) Acidic waters
c) High levels of calcium carbonate
d) Cold-water temperatures

Answer
c) High levels of calcium carbonate

Which of the following is an example of a detritivore in aquatic ecosystems?
a) Sea urchin
b) Tuna fish
c) Phytoplankton
d) Sea otter

Answer
a) Sea urchin

Which of the following is a characteristic of deep-sea ecosystems?
a) High levels of light penetration
b) Limited biodiversity
c) Warm temperatures
d) Abundance of plant life

Answer
b) Limited biodiversity

Which of the following is a common adaptation of marine mammals to their aquatic environment?
a) Gills for respiration
b) Lungs for breathing air
c) Scales for protection
d) Blubber for insulation

Answer
d) Blubber for insulation

Which of the following is a characteristic of rivers and streams?
a) High levels of salinity
b) Slow-moving water
c) Lack of vegetation
d) Flow of water in one direction

Answer
d) Flow of water in one direction

What is the term for the process by which dissolved oxygen is replenished in aquatic ecosystems through the interaction between air and water?
a) Photosynthesis
b) Osmosis
c) Diffusion
d) Aeration

Answer
c) Diffusion

Which of the following is an example of a lentic ecosystem?
a) River
b) Estuary
c) Lake
d) Coral reef

Answer
c) Lake

What is the term for the zone in a lake or pond where light penetrates and photosynthesis occurs?
a) Littoral zone
b) Limnetic zone
c) Profundal zone
d) Benthic zone

Answer
a) Littoral zone

Which of the following is an example of a macroinvertebrate commonly found in freshwater ecosystems?
a) Sea anemone
b) Coral
c) Dragonfly larva
d) Tuna fish

Answer
c) Dragonfly larva

What is the term for the process by which water is converted into water vapor and released into the atmosphere from aquatic ecosystems?
a) Precipitation
b) Condensation
c) Evaporation
d) Transpiration

Answer
c) Evaporation

Which of the following is a characteristic of kelp forests?
a) Low levels of productivity
b) Abundance of corals
c) Lack of biodiversity
d) High levels of productivity

Answer
d) High levels of productivity

Which of the following is a characteristic of oligotrophic lakes?
a) High nutrient levels
b) Murky water
c) Low levels of productivity
d) Abundance of algae

Answer
c) Low levels of productivity

What is the term for the zone in a lake or pond that extends beyond the littoral zone and is characterized by open water with abundant light penetration?
a) Littoral zone
b) Limnetic zone
c) Profundal zone
d) Benthic zone

Answer
b) Limnetic zone

Which of the following is a characteristic of marine ecosystems?
a) Low salinity
b) Limited biodiversity
c) High levels of dissolved oxygen
d) Lack of primary producers

Answer
c) High levels of dissolved oxygen

What is the term for the process by which aquatic organisms excrete waste nitrogen compounds, such as ammonia, into the surrounding water?
a) Osmoregulation
b) Filtration
c) Excretion
d) Nitrogen fixation

Answer
c) Excretion

Which of the following is an example of a nektonic organism?
a) Phytoplankton
b) Zooplankton
c) Tuna fish
d) Sea anemone

Answer
c) Tuna fish

What is the term for the process by which dissolved carbon dioxide is converted into inorganic carbonates in aquatic ecosystems?
a) Respiration
b) Decomposition
c) Photosynthesis
d) Carbonation

Answer
c) Photosynthesis

Which of the following is a characteristic of intertidal zones?
a) Consistent water levels
b) Limited exposure to air
c) Deep-water habitats
d) Lack of tidal changes

Answer
b) Limited exposure to air

What is the term for the process by which dissolved oxygen is consumed by aquatic organisms through respiration?
a) Photosynthesis
b) Diffusion
c) Osmosis
d) Oxygenation

Answer
b) Diffusion

Which of the following is a characteristic of brackish water ecosystems?
a) Low salinity
b) Limited biodiversity
c) Lack of vegetation
d) Mix of freshwater and saltwater

Answer
d) Mix of freshwater and saltwater

What is the term for the process by which aquatic organisms excrete excess water and maintain solute balance?
a) Osmoregulation
b) Filtration
c) Excretion
d) Nitrogen fixation

Answer
a) Osmoregulation

Which of the following is a characteristic of coral bleaching?
a) Increased diversity of coral species
b) Higher reproductive rates of corals
c) Loss of symbiotic algae from corals
d) Enhanced growth of coral reefs

Answer
c) Loss of symbiotic algae from corals

Which of the following is an example of a keystone species in aquatic ecosystems?
a) Clownfish
b) Sea urchin
c) Phytoplankton
d) Sea otter

Answer
b) Sea urchin

What is the term for the process by which heat is transferred from the surface of the ocean to the atmosphere?
a) Evaporation
b) Condensation
c) Convection
d) Radiation

Answer
a) Evaporation

Which of the following is a characteristic of lotic ecosystems?
a) High levels of salinity
b) Slow-moving water
c) Lack of vegetation
d) Flow of water in one direction

Answer
d) Flow of water in one direction

What is the term for the process by which dissolved carbon dioxide combines with water to form carbonic acid in aquatic ecosystems?
a) Respiration
b) Decomposition
c) Photosynthesis
d) Carbonation

Answer
d) Carbonation

Which of the following is an example of a sessile organism in aquatic ecosystems?
a) Fish
b) Phytoplankton
c) Zooplankton
d) Sea anemone

Answer
d) Sea anemone

What is the term for the process by which excess nutrients, such as nitrogen and phosphorus, are removed from wastewater before it is released into aquatic ecosystems?
a) Eutrophication
b) Biomagnification
c) Acidification
d) Water treatment

Answer
d) Water treatment

Which of the following is a characteristic of deep-sea hydrothermal vent ecosystems?
a) High levels of light penetration
b) Limited biodiversity
c) Warm temperatures
d) Absence of primary producers

Answer
c) Warm temperatures

What is the term for the process by which excess nutrients, such as nitrogen and phosphorus, enter freshwater ecosystems and cause excessive growth of algae?
a) Eutrophication
b) Biomagnification
c) Acidification
d) Desalination

Answer
a) Eutrophication

Which of the following is a characteristic of seagrass ecosystems?
a) Low productivity
b) Absence of biodiversity
c) Lack of vegetation
d) Protection against erosion

Answer
d) Protection against erosion

Which of the following is an example of a secondary consumer in aquatic ecosystems?
a) Phytoplankton
b) Zooplankton
c) Sharks
d) Seaweed

Answer
c) Sharks

What is the term for the process by which dissolved oxygen is produced in aquatic ecosystems through the photosynthetic activity of plants and algae?
a) Respiration
b) Decomposition
c) Photosynthesis
d) Oxygenation

Answer
c) Photosynthesis

Which of the following is a characteristic of freshwater wetlands?
a) High levels of salinity
b) Limited biodiversity
c) Waterlogged soils
d) Deep-water habitats

Answer
c) Waterlogged soils

What is the term for the zone in a lake or pond that extends beyond the littoral zone and is characterized by deep, dark water with low light penetration?
a) Littoral zone
b) Limnetic zone
c) Profundal zone
d) Benthic zone

Answer
c) Profundal zone

Which of the following is an example of a macrophyte commonly found in aquatic ecosystems?
a) Sea anemone
b) Coral
c) Seaweed
d) Tuna fish

Answer
c) Seaweed

What is the term for the process by which dissolved oxygen is consumed by decomposer organisms as they break down organic matter in aquatic ecosystems?
a) Photosynthesis
b) Diffusion
c) Osmosis
d) Oxygenation

Answer
b) Diffusion

Which of the following is a characteristic of polar marine ecosystems?
a) Low salinity
b) Limited biodiversity
c) Absence of ice
d) Cold-water temperatures

Answer
d) Cold-water temperatures

What is the term for the process by which excess water is removed from the body of an aquatic organism?
a) Osmoregulation
b) Filtration
c) Excretion
d) Nitrogen fixation

Answer
a) Osmoregulation

Which of the following is a characteristic of riparian zones?
a) High levels of salinity
b) Lack of vegetation
c) Absence of aquatic life
d) Proximity to rivers and streams

Answer
d) Proximity to rivers and streams

What is the term for the process by which excess carbon dioxide is removed from the atmosphere through the photosynthetic activity of aquatic plants and algae?
a) Respiration
b) Decomposition
c) Photosynthesis
d) Carbonation

Answer
c) Photosynthesis

Which of the following is an example of a pelagic organism?
a) Phytoplankton
b) Zooplankton
c) Sea anemone
d) Sea otter

Answer
a) Phytoplankton

What is the term for the process by which dissolved oxygen is replenished in aquatic ecosystems through the photosynthetic activity of plants and algae?
a) Photosynthesis
b) Osmosis
c) Diffusion
d) Oxygenation

Answer
a) Photosynthesis

Which of the following is a characteristic of salt marshes?
a) Low levels of salinity
b) Absence of vegetation
c) Oxygen-rich soils
d) Protection against tidal waves and erosion

Answer
d) Protection against tidal waves and erosion

What is the term for the process by which dissolved carbon dioxide is released into the atmosphere from aquatic ecosystems?
a) Precipitation
b) Condensation
c) Evaporation
d) Respiration

Answer
d) Respiration

Which of the following is a characteristic of pelagic ecosystems?
a) High levels of salinity
b) Limited biodiversity
c) Absence of primary producers
d) Open water habitats

Answer
d) Open water habitats

What is the term for the zone in a lake or pond that extends from the shoreline to the point where rooted plants no longer grow?
a) Littoral zone
b) Limnetic zone
c) Profundal zone
d) Benthic zone

Answer
a) Littoral zone

Which of the following is an example of a filter feeder in aquatic ecosystems?
a) Fish
b) Phytoplankton
c) Zooplankton
d) Sea anemone

Answer
c) Zooplankton

What is the term for the process by which dissolved oxygen is consumed by decomposer organisms as they break down organic matter in aquatic ecosystems?
a) Photosynthesis
b) Diffusion
c) Osmosis
d) Oxygenation

Answer
b) Diffusion

Which of the following is a characteristic of mangrove ecosystems?
a) High levels of salinity
b) Absence of vegetation
c) Oxygen-rich soils
d) Protection against tidal waves and erosion

Answer
d) Protection against tidal waves and erosion

What is the term for the process by which dissolved oxygen is produced in aquatic ecosystems through the photosynthetic activity of plants and algae?
a) Respiration
b) Decomposition
c) Photosynthesis
d) Oxygenation

Answer
c) Photosynthesis

Which of the following is an example of a sessile organism in aquatic ecosystems?
a) Fish
b) Phytoplankton
c) Zooplankton
d) Sea anemone

Answer
d) Sea anemone

What is the term for the process by which heat is transferred from the surface of the ocean to the atmosphere?
a) Evaporation
b) Condensation
c) Convection
d) Radiation

Answer
a) Evaporation

Which of the following is a characteristic of polar marine ecosystems?
a) Low salinity
b) Limited biodiversity
c) Absence of ice
d) Cold-water temperatures

Answer
d) Cold-water temperatures

 

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