L4 Origin of Prokaryotes and Eukaryotes

Question 1

What are the three types of fossil evidence for prokaryotic life in context with rocks?

Answer 1

1. Fossil stromatolites
2. Fossil Microorganisms
3. Carbonaceous matter that can be identified chemically as the product of ancient life.

Question 2

What are the two types of fossil microorganisms?

Answer 2

1. 2a silicified in cherts
2. 2b resistant cell walls called acritarchs preserved in siltstones.

Question 3

Are prokaryotes relatively unchanged to the present day?

Question 4

By 3.5 Billion years we have advanced prokaryote life, what does it consist of?

Answer 4

This consisted of complex and diverse communities of stromatolite forming communities on the floors of shallow seas and free living prokaryotes floating around in the oceans.

Question 5

What were the two communitites of prokaryote present at 3.5 Bill?

Answer 5

autotrophic cyanobacteria (that produce oxygen as a biproduct of their photosynthetic metabolism) and heterotrophic consumers that sweep up waste products.

Question 6

Explain early oxygen sinks.

Question 7

What is Great Oxygenation Event?

Question 8

What are the two considerations for the origin of eukaryotes?

Answer 8

1. When were conditions suitable
   for the origin of eukaryotes.
2. Fossil evidence for eukaryotes

Question 9

What are the two theories regarding the origination of the eukaryote cell?

Answer 9

1. Symbiosis
2. Elaboration of the cell membrane

Question 10

Explain Theory 3 - multiple symbiotic evenets.

Question 11

Symbiotic origin of chloroplasts?