G3 Origin of species.

Question 1

What is LIFE defined as by nasa?

Answer 1

Life = Any system that Shows DARWINISM evolution

Question 2

What was Darwin’s origin of life idea 9 (theory 1)

Answer 2

Darwin suggested origin of life was 4 billion years ago
- unlikely as 4 billion years ago;
* continuous bombardment + very high UV at surface as SUN is strong and young= repeated water bombardment bring water and destruction.
* Any DNA or RNA molecule would be fried in these conditions
Darwin’s origin of life idea, (warm muddy pond)which is very NOT LIKELY
Theory 2:

Question 3

Describe theory 2 for evolution

Answer 3

3.8 Billion Years ago when the firsts organisms came around, we know this by tracing back using the molecular clock.
Energy to fuel first replicating molecules may have come from proton gradients around alkaline hydrothermal vents in the seas
All life Is based on energy (e.g. Sun), so theoretically you would be needing energy to ‘start life’
3.8 billion years ago in the DEEP SEA: contact between alkaline water and acidic water in the sea, this causes movement of protons, movement of protons equals to energy. This energy could have been the source of energy for the little organisms that came around 3.8 billion years.

Question 4

Describe the RNA world theory.

Answer 4

Theory 3: RNA world
RNA is the key to everything in the body for example reduction of protein where DNA is just a library containing generic infestation.
RNA carries information but it’s also an enzyme
1.Prebiotic chemistry where you just have molecules fiddling around (4.2 billion ya)
2.Pre- RNA world = Simpler biomolecules would, through evolution, become what eventually became RNA.
3.You have an RNA world
4.RNA world starts to produce proteins/amino acids eventually leading to formation of DNA which eventually meet as they’re just molecules floating around

Question 5

What was the issues of the molecules such amino acids, DNA,RNA and their survival in the early world?

Answer 5

Conditions were too harsh for these molecules to survive, 4 bya

Question 6

Gives 2 theories with which DNA and RNA could’ve survived without a cell in the harsh conditions 4bya

Answer 6

• DNA and RNA could’ve ‘met’ in tiny pores in rocks vent which might have acted as cell
  Another hypothesis could be through lipid PROTOBIONTS: protobionts is the aggregation of organic and inorganic molecules surrounded by membrane lipid bilayer; RNA might have encountered these lipid protbionts are reproduced within them, eventually forming cells.

Question 7

What is the great oxidation event?

Answer 7

• First prokaryotes were methane-producing bacteria
  
  • O2 IS STILL LOW IN THE ENVIRONMENT (< 0.001% of current levels)
  • Cyanobacteria use photosynthesis (aka blue-green algae) to produce O2
  • For hundreds of millions of years, this O2 consumed by methanogenic bacteria
• Most methanogens eventually die out due to RANDOM EFFECTS, perhaps due to changes in trace metals in sea
  As most methanogens die, the the O2 is not used up anymore and by methanogens, so cyanobacteria continue to produce o2 which increases drastilcally

Question 8

What is EUKARYOGENESIS

Answer 8

Its the formation of Eukaryotes

Formation of eukaryotes happened only once ( from 4.8 billion years ago, it happened the first time 2.8 years ago, eventually leading to us)

Question 9

Explain what theory could describe, the formation of EUKARYOTIC cells, both plants/animals. (from formation of mitochondria)

Answer 9

· An Archaebacterium casually BUMPS and then engulfs heterotrophic eubacterium which eventually becomes mitochondria
· Heterotrophic bacteria did not die as it was engulfed by archaebacterium, it was just stolen
· Eventually it adapted to live inside cell, forming mitochondria
· Mitochondria then was engulfed/stolen by a EUKRYOTIC PLANT ANCESTOR, forming chloroplast.
· We are a product of a chance event!
· Energy provided by mitochondria allows for large, complex life.
· This is not the PRODUCT OF NATURAL SELECTION

Question 10

What is the CAMBRIAN EXPLOSION

Answer 10

refers to an interval of time approximately 538.8 million years ago in the Cambrian Period when practically all major animal phyla started EXPONENTIALLY appearing in the fossil record.

Question 11

Causes of CAMBRION EXPLOSION: THEORIES

Answer 11

Physiological change – dissolved oxygen levels allowed more active lifestyle (faster/stronger organisms)

Geographical change – new seas, new niches?

Geochemical change – sea-level changes-> abundance of trace metals to make exoskeletons