1.2 Three Domain of Life Flashcards
What is the origin of life?
Panspermia: Life originated from microorganisms or chemical precursors of life from outer space and were able to initiate life after reaching earth
What is the theory of Chemical Evolution
or Abiotic Synthesis?
The formation of complex organic molecules from simpler inorganic molecules through chemical reactions in oceans during the early history of earth
AKA PROTOCELL
What was primitive earf be lyke?
The primitive earth was hot,
anaerobic with warm oceans
A lot of volcanic activity, meteorites
& radioactivity
What was critical to primitive earf?
Absence of O2
What type of gases existed in primitive earf?
Simple organic molecules formed
from CH4, CO2, H2, N2, NH3 gases
dissolved in the oceans
Building organic molecules requires ________
Electrons
The lack of O2 in the atmosphere of the early earth’s atmosphere favored the synthesis of \_\_\_\_\_\_\_\_ molecules
organic
AKA reduces atmpsophere
Why was the Murchison Meteorite so important?
Discovered amino acids and organic compounds that are similar to ones found in cells
Astrobiology? What it be?
Study of the origin,
evolution, distribution and
future of life in the universe
What is the Cambrian Explosion?
Started 545 mya By 600 mya fossil ancestors of crustaceans, starfish, sponges, mollusks, worms, chordates and algae
Microorganisms existed for
~________ billion years before
multicellular organisms
3.2-3.5
The 1st cells were _______________
marine
prokaryotic anaerobes
Multicellular bodies with
bilateral symmetry were
not present before _____ mya
600
Multicellular organisms
with a body appear in the
fossil record ______ million
years ago
600
What are Stromatolites?
Microbial fossils in
layered sedimentary rock
Just fossils, no living things
