History Of Life On Earth Flashcards
Steps that made the origin of life possible
- Organic molecules formed abiotically
- Small organic molecules formed into macromolecules
- Macromolecules formed membranes
- Macromolecules self-replicated, making inheritance possible
Amino acids turns into…
Proteins
Nucleotides turn into…
Nucleoacids
Fatty acids and glycerol turns into…
Lipids
What is the primitive soup hypothesis?
Organic compounds form from simpler molecules with energy from lightning, volcanic eruptions, and IV radiation
What is primitive soup evidence?
Urey and Miller experiment tested this hypothesis
Created lab conditions comparable to those on early Earth
Produced many amino acids found today and other organic compounds
Experiment has been repeated many times since
What is the deep sea vent hypothesis?
Organic compounds are produced in deep-sea hydrothermal vents
What is a hydrothermal vent?
Areas on the sea floor where heated water and minerals gush from Earth’s interior into the ocean
What is astrobiology?
The study of life in the universe
Hypothesis for astrobiology:
Organic compound delivered to earth by meteorites and other celestial objects
What is comet 67P?
Discovered in 2014
Found amino acid glycine
What is Murchison meteorite?
Discovered in 1969
4.5 billion years old
Contained 80+ amino acids
Very cell has many types of…
Macromolecules
Packing of molecules into…
Protocells
All organisms must carry out…
Reproduction and energy processing (metabolism)
Key Events of the History of Life
- first organisms evolve (prokaryotes)!
- oxygen-generating photosynthesis
- first single celled eukaryotes
- first multicellular eukaryotes
- diversification of animals
- plants colonize land
- humans evolve
What were the first organisms to evolve?
prokaryotes
oldest known fossil organisms are contained in…
stromatolites
what are stromatolites?
type of rock formed by accumulation of layers (and layers and layers) of prokaryotic bacteria
What are photosynthetic prokaryotes?
the first photosynthesizers
single celled organisms with a nucleus evolved from…
prokaryotes
unicellular eukaryotes include…
some algae, some fungi, slime mold
What is the endosymbiotic theory?
theory that eukaryotes originated from prokaryotes through endosymbosis
What does endosymbiont?
means a cell that lives within a host cell
mitochondria and chloroplasts have their own DNA separate from…
DNA in nucleus that is similar in shape to prokaryotes
size of mitochondria and chloroplasts are similar to…
prokaryotes
when mitochondria and chloroplasts divide its similar to…
prokaryotes
endosymbiotic theory is the explanation for…
how prokaryotes evolved into modern eukaryotes
multicellularity has evolved multiple times across…
the tree of life
multicellular eukaryotes is linked to…
increased atmospheric oxygen
what is the cambrian explosion?
many present day animal groups appear suddenly in fossil record 535-525 million years ago
20-35 major phyla evolve
adaptations during the Cambrian
development hard barts (claws, shells armour)
flexible limbs
eyes
predator prey relationships arise
complex ecosystems evolve
larger forms of life did not colonize land until…
500 million years ago
plants lived on land…
first
fungi likely co-evolved on land with…
plants
why was the colonization of land important?
nutrients scavenged from rocks to form soil
atmospheric oxygen levels rose
plants provided food for other organisms
only 9 of the 58 animal groups are…
found on Earth today
the earliest land animals were…
arthropods
