the origin of life

Question 1

what are the phases of the first cells

Answer 1

1) the abiotic ( the creation of organic molecules from non-life) synthesis of small organic molecules (monomers)

2) the joining of monomers into polymers

3) the packaging of these molecules into protobionts (first formed cells)

4)origin of self-replication molecules that would make inheritance possible

Question 2

how long ago was the origin of earth

Answer 2

4.6 billion years ago

Question 3

how long ago were the earliest cells (prokaryote microfossils)

Answer 3

3.5 billion years ago

Question 4

how long ago were the oldest eukaryote fossils

Answer 4

1.7 billion years ago

Question 5

what are the 4 requirements necessary for the creation of organic chemicals from simple molecules

Answer 5

1) no free oxygen
2) source of energy
- volcanism, thunderstorms, lighting uv radiation
3) chemical building blocks
- water, ions, and dissolved
4) lots of time

Question 6

what did experiments show about protobionts

Answer 6

they exhibit some properties of life

Question 7

for phase 4), what was thought to have originated first

Answer 7

• RNA

Question 8

what are stromatolites

Answer 8

• first cells , prokaryotes
• rocklike structures composed of layers of bacteria and sediment

Question 9

how long ago did eukaryotes arise from prokaryotes

Answer 9

2.1 BYA

Question 10

what is the endosymbiotic theory

Answer 10

mitochondria and chloroplast derived from prokaryotes that were ingested and became mutually beneficial

Question 11

what is the evidence supporting the endosymbiotic theory

Answer 11

• chloroplasts and mitochondria are about the size of bacteria
• both have double membrane
• both have circular DNA
• both have ribosomes and protein synthesis machinery

Question 12

what is the primitive soup hypothesis

Answer 12

According to the theory, organic compounds essential for life forms were synthesized in the primitive Earth under prebiotic conditions. The mixture of inorganic and organic compounds with water on the primitive Earth became the prebiotic or primordial soup.

Question 13

how long aho did eukaryotes arise from prokaryotes

Answer 13

2.1 BYA

Question 14

what are the 3 different perspectives of biodiversity

Answer 14

1) genetic diversity
2) ecosystem diversity
3)species diversity

Question 15

what is genetic diversity

Answer 15

• total genetic info contained in all individuels of a species
• is dynamic , can change with natural selection, immigration
• changes in the allele distributions within a pop or species

Question 16

what is ecosystem diversity

Answer 16

• total variety of ecosystems in an area
• (tundra/rocky/boreal forest)
• is dynamic : changes in climate can form new ecosystems or modify old ones

Question 17

what is species diversity

Answer 17

• total variety of species within a region
• is dynamic, can increase with speciation (new species) and decrease with extinction

Question 18

when was the oxygen revolution

Answer 18

2.4 bya to 2 bya

Question 19

what allowed for heterotrophs to emerge

Answer 19

autotrophs

Question 20

what caused autotrophs to emerge

Answer 20

limited supply of natural organic molecules

Question 21

when was the origin of life

Answer 21

3.7-3.8 BYA