Q 01/05

Which continent is classed as the largest desert on Earth?

A) Australia

B) North America

C) Antarctica

D) South America

Answer · why

C) Antarctica

Antarctica is a polar desert because so little snow falls there, and at about 14 million square km it is far bigger than the Sahara.

Q 02/05

Camels keep going when desert food is scarce by drawing on which substance stored in their humps?

A) Water

B) Fat

C) Salt

D) Blood

Answer · why

B) Fat

Fat fills a camel's hump, not water, and a camel that burns through its reserve is left with a hump that goes limp and droops.

Q 03/05

Which ocean habitat covers less than 0.1% of the sea yet shelters at least a quarter of all marine species?

A) Coral reefs

B) Seagrass meadows

C) Salt marshes

D) Oyster beds

Answer · why

A) Coral reefs

Coral reefs occupy an area only about half the size of France, and the largest barrier reef of all is Australia's Great Barrier Reef.

Q 04/05

Which conifer-forest biome, ringing the far north through Canada and Russia, is the largest on land?

A) Steppe

B) Tundra

C) Chaparral

D) Taiga

Answer · why

D) Taiga

Taiga is also known as boreal forest or snow forest, and its freezing winters last five to seven months of the year.

Q 05/05

Which desert, the driest non-polar place on Earth, is used to test instruments for Mars missions?

A) Mojave

B) Atacama

C) Sonoran

D) Kalahari

Answer · why

B) Atacama

The Atacama averages about 15 mm of rain a year, and some of its weather stations have never recorded any at all.