Q 01/05

Which is the smallest and shallowest of Earth's five oceans?

A) Arctic Ocean

B) Southern Ocean

C) Indian Ocean

D) Atlantic Ocean

Answer · why

A) Arctic Ocean

The Arctic Ocean is mostly covered by sea ice, which reflects far more of the Sun's energy than open water, so as the ice melts, the darker water abso...

Q 02/05

In which sea creature does the male, rather than the female, carry the young and give birth?

A) Seahorse

B) Sea turtle

C) Dolphin

D) Swordfish

Answer · why

A) Seahorse

Seahorses: the female places her eggs in the male's brood pouch, and he carries them for weeks before pushing the young out with muscular contractions...

Q 03/05

Ocean phytoplankton produce about half of Earth's oxygen through which process?

A) Chemosynthesis

B) Photosynthesis

C) Fermentation

D) Respiration

Answer · why

B) Photosynthesis

Photosynthesis: because phytoplankton need light to make food, they drift in the ocean's top layer, and they form the base of most marine food webs.

Q 04/05

Which sea creature's internal shell gives pet birds extra calcium?

A) Nautilus

B) Cuttlefish

C) Squid

D) Sea urchin

Answer · why

B) Cuttlefish

Cuttlefish: the cuttlebone is divided into chambers, and the animal changes their mix of gas and liquid to rise or sink.

Q 05/05

Which whale migrates each year between icy northern feeding grounds and calving lagoons in Mexico's Baja California?

A) Sperm whale

B) Gray whale

C) Minke whale

D) Orca

Answer · why

B) Gray whale

Gray whales make one of the longest annual migrations of any mammal, and after whaling drove them to near extinction, the eastern population recovered...