Q 01/05

Which group of living animals descends from theropod dinosaurs, making its members the only dinosaurs alive today?

A) Crocodiles

B) Birds

C) Lizards

D) Turtles

Answer · why

B) Birds

Birds evolved from small theropods, the two-legged group that also produced Tyrannosaurus rex. Their closest living relatives are the crocodilians.

Q 02/05

About how old is Earth, an age roughly one-third that of the universe itself?

A) 45 million years

B) 450 million years

C) 4.5 billion years

D) 45 billion years

Answer · why

C) 4.5 billion years

4.5 billion years ago the planet was largely built within 10 to 20 million years, a quick start to a very long story.

Q 03/05

Which crater, found by geophysicists prospecting for oil, marks the asteroid strike that doomed the dinosaurs?

A) Chicxulub

B) Vredefort

C) Manicouagan

D) Popigai

Answer · why

A) Chicxulub

Chicxulub lies under about a kilometre of younger rock on Mexico's Yucatán Peninsula, which is why it stayed hidden. The asteroid that blasted it out ...

Q 04/05

Which supercontinent held nearly all of Earth's land before it began to break apart during the Mesozoic Era?

A) Gondwana

B) Rodinia

C) Laurasia

D) Pangaea

Answer · why

D) Pangaea

Pangaea was surrounded by a single superocean, Panthalassa. Its name comes from Greek words for 'all' and 'Mother Earth'.

Q 05/05

Which gas, toxic to much early life, did cyanobacteria release into Earth's air as a by-product of photosynthesis?

A) Oxygen

B) Methane

C) Nitrogen

D) Ammonia

Answer · why

A) Oxygen

Oxygen began building up in the air about 2,400 million years ago, a turning point known as the Great Oxidation Event. The gas may have killed off man...