Question

select the correct answer.
what differentiates sharks from whales?
a. sharks have a dorsal fin and whales only have lateral flippers.
b. sharks are toothed cetaceans and whales are baleen cetaceans.
c. sharks can breathe underwater while whales have to surface to breathe.
d. sharks eat fish and larger creatures while whales eat only krill.
e. sharks have smooth skin while whales have scaly skin.
reset

Explanation:

• Option A: Both sharks and whales have dorsal fins. Whales also have other fins. So this option is incorrect.
• Option B: Sharks are not cetaceans. Cetaceans are a group of marine mammals (whales, dolphins, porpoises). So this option is incorrect.
• Option C: Sharks have gills and can extract oxygen from water (breathe underwater). Whales are mammals and need to come to the surface to breathe air. This is a key difference.
• Option D: Some whales (like killer whales - which are actually dolphins, a type of cetacean) eat fish and larger creatures. Baleen whales mainly eat krill, but not all whales. So this option is incorrect.
• Option E: Sharks have rough, sand - paper like skin (placoid scales). Whales have smooth skin. So this option is incorrect.

Answer:

C. Sharks can breathe underwater while whales have to surface to breathe.