Origin of Life Flashcards
Main theories on the origin of life (7)
- Theory of Creation
- Abiogenesis (Theory of Spontaneous Generation)
- Biogenesis
- Cosmozoic/Interplanetary Hypothesis
- Natural or Marine (Primeval Soup)
- Physico-chemical/Coacervate Droplet Theory
- Evolution Theory
3 Possibilities
Special Creation
Extraterrestrial Origin
Spontaneous Origin
Life-forms may have been put on Earth by supernatural or divine forces
Special Creation
Life may not have originated on Earth at all; Instead, life may have infected Earth from some other planet.
Extraterrestrial Origin
Life may have evolved from inanimate matter, as associations among molecules become more and more complex
Spontaneous Origin
The ancient atmosphere is a ___ atmosphere.
Primitive Earth lacks ___ in the atmosphere.
UV rays from the sun can be ___ to living organisms.
reducing, protective layer, detrimental
It is believed that the ancient atmosphere was principally made up of 3 things:
Carbon dioxide (CO2)
Nitrogen Gas (N2)
Water Vapor (H2O)
It is believed that the ancient atmosphere could also possibly have: (3)
Hydrogen sulfide (H2S)
Ammonia (NH3)
Methane (CH4)
Other Hypotheses: (4)
a) Under frozen oceans
b) Deep in the earth’s crust
c) within clay
d) Deep-sea vents
In 1988, he proposed that life might have formed as a by-product of volcanic activity, with iron and nickel sulfide materials acting as chemical catalysts to recombine gases spewing from eruptions into the building blocks of life.
Gunter Wachtershauser
In the hypothesis of deep in the earth’s crust, what were the two chemical catalysts used to recombine gases spewing from eruptions into the building blocks of life?
Iron and Nickel Sulfide minerals
The surface of clays have ___ charges to attract organic molecules, and exclude water, providing a potential catalytic surface on which life’s early chemistry might have occured
positive
In deep-sea vents, the ___ of the ___ would have acted as a magnet for ___ ____.
positive charge, sulfides
negatively charged, organic molecules
suggests that the ancestors of today’s prokaryotes are most closely related to the bacteria that live on the deep-sea vents.
Genomics
Rocky structures in the sea floor caused by
lime-secreting cyanobacteria
rocky structures in the sea floor, where layers of fine sediments are built up with the help of tiny organisms
They contain the oldest piece of evidence of life about 3.5
billion years old.
Structure made by living things.
Stromatolites
Suggested that cyanobacteria raised oxygen levels in the atmosphere
Great Oxidation Event - 2.4 billion years ago
Poisonous waste produced by cyanobacteria
Oxygen
___ oxygen makes the iron in the oceans ___ and sink to the seafloor, forming striking banded iron formations
dissolved, rust
Provides protective covering from the harmful rays of the sun.
Ozone layer
2.3 billion years ago, Earth may have frozen over into the first “___” possibly as a result of a lack of volcanic activity.
snowball Earth
2 billion years ago, the group of bacteria evolved the ability to capture the energy of light
Some are photosynthetic such as plants and algae
Eukaryotic cells
Prokaryote traits (5)
No nucleus
No organelles
Very small
DNA is not as complex
Undergo Binary fission
Eukaryote traits (5)
Have a Nucleus
Have Organelles
Larger
Complex DNA
Undergo Mitosis and Meiosis
