Early Earth and Origin of Life
Free Response-like Questions
Respond to the following two prompts on a separate sheet of paper.
1. Our atmosphere may be the single most important factor in the development of life on our planet. The
primordial earth had no atmosphere. Explain how our original atmosphere was formed, what it was
composed of and if it was conducive to the formation of living organisms.
2. The formation of the first living organism is still a mystery. Outline and explain the empirical
(experimental or physical) evidence that may explain the origin of life here on earth. Also explain
where the original organisms had to have lived and why.
Scoring Guidelines
1. 3 points maximum (1 point per row)
Explain how original atmosphere
was formed
What original atmosphere
was composed of
Thick chunks of rock, ice and debris colliding
Water vapor
Volcanic eruptions and deep sea vents
released gases into atmosphere
Earth cooling
NO2, CO2, CH4, H2S, NH3, H2
Liquid water and a reducing
environment
If atmosphere was conducive to
formation of living organisms
Not conducive for life formation due to high
temperatures
Not conducive to life formation

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Conducive due to the formation of
organic compounds formed from simpler
molecules
Conducive as water condensed into
oceans; habitat for early life forms
2. 4 points maximum
Empirical evidence
(1 point for each piece of evidence)
Explain
(1 point for each explanation)
Formation of amino acids and other organic
compounds
Simulation to mimic early earth conditions consisting of water vapor, inorganic
compounds, and cooling
Formation of RNA polymers





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Production of organic molecules through
mineral catalysts
Nucleotides such as adenine could be synthesized in outer space or under early
earth conditions.
Aided by mineral catalysts to form polymers
Folding of RNA conferred catalytic properties to copy itself accurately
Facilitated biochemical reactions leading to production of organic compounds
Served as a platform for formation of first membrane
Formation of organic molecules surrounding metal as seen in present day
molecules
2 points maximum
Explanation of where original
organisms had to live
(1 point)
Near or in cooled water
Explain
(1 point for each explanation)


Ideal medium for chemical reactions such as metabolism and replication
Contained building blocks “primitive soup” needed to form life