Marine Biology MCQs

1. What is the primary focus of marine biology?

(A) Study of marine organisms and their ecosystems

(B) Study of terrestrial plants

(C) Study of freshwater systems

(D) Study of meteorological phenomena

2. Which of the following is a characteristic of plankton?

(A) They are primarily benthic organisms

(B) They are large and can be easily seen with the naked eye

(C) They are stationary and fixed to the ocean floor

(D) They drift with ocean currents and cannot swim actively

3. What is the primary role of phytoplankton in marine ecosystems?

(A) Decomposition of organic matter

(B) Providing shelter for marine organisms

(C) Primary production through photosynthesis

(D) Filtering pollutants from water

4. Coral reefs are primarily composed of:

(A) Algae

(B) Seaweed

(C) Fish

(D) Coral polyps

5. Which of the following is a major threat to coral reefs?

(A) Ocean acidification

(B) Increased water temperature

(C) Overfishing

(D) All of the above

6. The “benthic zone” in marine environments refers to:

(A) The surface layer of the ocean

(B) The open water column

(C) The ocean floor and its associated habitats

(D) The area near the shore

7. Which type of marine organism is known for its ability to produce bioluminescence?

(A) Sea anemones

(B) Sharks

(C) Jellyfish

(D) Sea turtles

8. The term “thermocline” refers to:

(A) The layer of the ocean where temperature changes rapidly with depth

(B) The layer of the ocean where salinity changes with depth

(C) The region where marine organisms live

(D) The boundary between the ocean and the atmosphere

9. Which of the following is a major component of the ocean’s nutrient cycle?

(A) Nitrogen

(B) Carbon

(C) All of the above

(D) Phosphorus

10. The “pelagic zone” is characterized by:

(A) The deepest parts of the ocean

(B) The open ocean away from the coast

(C) The intertidal zone

(D) The coastal and estuarine areas