Precambrian Earth and Life history

Question 1

what does an organism need to do to be considered living

Answer 1

1. metabolism
2. reproduction

Question 2

what are the basic requirements for life

Answer 2

1. energy
2. safe environment/good living conditions
3. elements (carbon)

Question 3

what are the 5 main kingdoms of life

Answer 3

1. animals
2. plants
3. protist
4. fungi
5. Monera

Question 4

how old are the oldest fossils

Answer 4

3.5 Ga years old, but could be older

Question 5

what is abiogenesis

Answer 5

life arising from non living matter

Question 6

what is Panspermia/ Universal seeding

Answer 6

life was brought to earth by meteorites

Question 7

what were the first organisms on earth

Answer 7

prokaryotes

Question 8

what are the characteristics of prokaryotes

Answer 8

• unicellular
• anaerobic (dont need oxygen)
• heterotrophic (cannot make own food)
• asexual (genes come from one parents only)

Question 9

what are the characteristics of Archaea

Answer 9

• similar to bacteria
• live in extreme environments
• dont exist as fossils

Question 10

what are the two ways 02 could have gotten into the atmosphere

Answer 10

1. photochemical dissociation
2. Photosynthesis

Question 11

how does Photochemical dissociation work

Answer 11

• UV radiation disrupts h20 in atmosphere, which releases o and h
• which eventually leads to oxygen formation in Ozone layer

Question 12

how does photosynthesis work

Answer 12

organisms take in CO2, water, sunlight to produce organic compounds and oxygen

Question 13

What happened when O2 increased and CO2 decreased

Answer 13

lead to appearance of autotrophic organisms like Stromatolites

Question 14

what is so significant about Stromatolites

Answer 14

• first to photosynthesis
• appeared in 3.5-3.0 Ga

Question 15

what is the Great Oxygenation Event

Answer 15

Fast rise in Atmospheric oxygen
about 2.4 billion years ago