In multicellular organisms, how can they get variation of DNA?
With a high rate of mutations
With sexual reproduction
Only with recombination
Why did the ozone layer allow life on land?
It protected from U.V radiation
It protected from very high oxygen concentration
It protected from high temperatures
List the 3 eras that make up the Phanerozoic Eon
Paleozoic, Mesozoic and Phanerozoic
Paleozoic, Mesozoic and Cenoloic
Paleozoic, Mesozoic and Cenozoic
What was the Cambrian Explosion?
A period of high rate of volcanic activity
An great increasing of biodiversity
The killing of the most of microorganisms
Where did the meteorite that wiped out dinosaurs fall?
In the Gobi desert
In the middle of the Atlantic Ocean
In the Yucatán Peninsula
Which one of this two appeared before, flowers or grass?
Flowers and then grass
Grass and then flowers
Both of them at the same time
How old is our specie?
20000 years ago
200000 years ago
2000000 years ago