Podcast
Questions and Answers
What were the dominant gases in Earth's early atmosphere?
What were the dominant gases in Earth's early atmosphere?
- Oxygen, methane, and water vapor
- Carbon monoxide, sulfur dioxide, and nitrogen
- Helium, oxygen, and nitrogen
- Hydrogen, nitrogen, and carbon dioxide (correct)
How do methanogens produce energy?
How do methanogens produce energy?
- $CO2 + 4H2 \rightarrow CH4 + 2H2O +$ energy (correct)
- $H2O + 4CO2 \rightarrow CH4 + 2H2O +$ energy
- $N2 + 3H2 \rightarrow NH3 + 2H2O +$ energy
- $CH4 + 2O2 \rightarrow CO2 + 2H2O +$ energy
What determines the amount of isotopic fractionation?
What determines the amount of isotopic fractionation?
- The temperature and pressure of the environment
- The concentration of isotopes present
- The distance from the equator
- The nature and strength of the process responsible for the sorting (correct)
What makes isotopes behave differently from one another?
What makes isotopes behave differently from one another?
What is the equation for calculating the δ13C value?
What is the equation for calculating the δ13C value?
What is the reference material for δ13C value?
What is the reference material for δ13C value?
During methanogenesis, archaea preferentially take up which isotope by up to 60 per mil?
During methanogenesis, archaea preferentially take up which isotope by up to 60 per mil?
What is the approximate age of the fluid inclusions with δ13C value of -60 per mil?
What is the approximate age of the fluid inclusions with δ13C value of -60 per mil?
What is the primary source of nitrogen for most organisms?
What is the primary source of nitrogen for most organisms?
What process fixes nitrogen primarily on land?
What process fixes nitrogen primarily on land?
What is the equation for the process of fixing nitrogen from N2 to NH3?
What is the equation for the process of fixing nitrogen from N2 to NH3?
What is the source of energy for fixing nitrogen?
What is the source of energy for fixing nitrogen?
What event led to the rise of oxygen in the atmosphere?
What event led to the rise of oxygen in the atmosphere?
What caused the fractionation of sulfur isotopes in the presence of O2?
What caused the fractionation of sulfur isotopes in the presence of O2?
At what approximate time did O2 rise to appreciable levels?
At what approximate time did O2 rise to appreciable levels?
What is the primary source of energy for early life in the Archean Eon?
What is the primary source of energy for early life in the Archean Eon?
