More cards in this set

What were the first organisms that appeared?

What evolved next?

What was produced due to this?

What happened next?

What caused the first animal to be evolved?

What happened to micro-organisms that couldn't tolerate high oxygen level?

What happens to the carbon dioxide taken in during photosynthesis?

These skeletons and shells built up at bottom of oceans, what next?

What happened to some of the remains of ancient living things?

What did these form?