History of Life on Earth

Question 1

What are the 4 geological eons

Answer 1

Hadeon
Archaeon
Proterozoic
Phanerozoic

Question 2

2 Outcomes of Hadeon

Answer 2

Giant impact hypothesis - Formation of the moon
Late heavy bombardment - Bombardment of meteorites and debris

Question 3

Main outcome of Archaeon

Answer 3

Presence of Prokaryotes

Question 4

Main outcome of Proterozoic

Answer 4

Presence of eukaryotes

Question 5

3 Main emergences of phanerozoic

Answer 5

Marine Fauna, angiosperms and dinosaurs

Question 6

What rocks contains the earliest evidence of life on earth and what life are they evidence of

Answer 6

Stromatolites and cyanobacteria

Question 7

4 main stages of Abiogenesis Hypothesis

Answer 7

1. Abiotic formation of small organic molecules
2. Joining of molecules into macromolecules
3. Packaging of molecules into protocells
4. Origin of self-replication molecules

Question 8

Describe how the presence of prokaryotes led to eukaryotes including oxygen level changes

Answer 8

• Prokaryotes photosynthesise releasing oxygen
• This oxygen dissolves into the sea until water becomes saturated and oxygen gases out
• Oxygen released led to extinction of most prokaryotes and adaptation of cellular respiration
• Endosymbiosis of prokaryotes led to formation of eukaryotes

Question 9

How long ago was and what caused the Cambrian explosion

Answer 9

540 mya - Rise in atmospheric oxygen levels

Question 10

Main cause of mass extinction and how many have there been

Answer 10

Volcanic eruptions - 5

Question 11

How old is the earth and when did life on earth begin

Answer 11

4.55 bya and 3.5 bya