PADI Marine Biology & Conservation 5

Question 1

What is the ecological role of apex predators like sharks in a marine food web?

Accepted Answer

They regulate prey populations and maintain ecosystem balance

Answer

Apex predators control prey populations and prevent overgrazing of critical habitats; their removal triggers trophic cascades that destabilize entire ecosystems.

Question 2

Which structure in a bony fish controls its buoyancy by adjusting the volume of gas inside?

Accepted Answer

Swim bladder

Answer

The swim bladder is an internal gas-filled organ that fish inflate or deflate to achieve neutral buoyancy at various depths without constant swimming effort.

Question 3

What is the 'bleaching threshold' of water temperature for most tropical coral reef systems?

Accepted Answer

1°C above the average seasonal maximum sustained for several weeks

Answer

Coral bleaching is typically triggered when water temperatures exceed the seasonal maximum by just 1°C for several weeks, causing corals to expel their symbiotic zooxanthellae.

Question 4

What is meant by the term 'trophic level' in marine biology?

Accepted Answer

The organism's position in a food chain based on its energy source

Answer

Trophic level describes an organism's position in a food web; producers are level one, herbivores level two, and predators occupy progressively higher levels.

Question 5

Which global initiative does PADI support that asks divers to report marine life sightings to contribute to scientific databases?

Accepted Answer

Both Project AWARE and Reef Check

Answer

PADI supports both Project AWARE (ocean protection, debris reporting, shark and ray data) and Reef Check (coral reef monitoring surveys) as citizen science programs for divers.

(PADI) Certified Professional Association of Diving Instructors Diver Practice Test

(PADI) Certified Professional Association of Diving Instructors Diver Practice Test

PADI Marine Biology & Conservation 5