Podcast
Questions and Answers
Which gases were likely present in Earth's first atmosphere?
Which gases were likely present in Earth's first atmosphere?
- Hydrogen and helium (correct)
- Ammonia and methane
- Oxygen and nitrogen
- Carbon dioxide and water vapor
What caused Earth's second atmosphere?
What caused Earth's second atmosphere?
- Chemical reactions in the oceans
- Volcanic outgassing (correct)
- Meteor impacts
- Photosynthesis by early organisms
Why was there very little oxygen in Earth's second atmosphere?
Why was there very little oxygen in Earth's second atmosphere?
- It was not produced yet
- It reacted with other elements (correct)
- It was absorbed by the oceans
- It was consumed by early organisms
Which two scientists proposed nearly identical hypotheses for the steps of how life could have originated on Earth?
Which two scientists proposed nearly identical hypotheses for the steps of how life could have originated on Earth?
What is the final step proposed by Oparin and Haldane for the origin of life on Earth?
What is the final step proposed by Oparin and Haldane for the origin of life on Earth?
Which type of molecules can be large with many atoms and are usually associated with living organisms?
Which type of molecules can be large with many atoms and are usually associated with living organisms?
What is the first step in the Oparin-Haldane origin of life hypothesis?
What is the first step in the Oparin-Haldane origin of life hypothesis?
Which type of molecules contain carbon and hydrogen and are usually associated with living organisms?
Which type of molecules contain carbon and hydrogen and are usually associated with living organisms?
What is the first step in the Oparin-Haldane origin of life hypothesis?
What is the first step in the Oparin-Haldane origin of life hypothesis?
Which process do most living things use to get the energy to synthesize molecules?
Which process do most living things use to get the energy to synthesize molecules?
How did organic molecules form from inorganic precursors on early Earth?
How did organic molecules form from inorganic precursors on early Earth?
Which experiment demonstrated evidence for the origin of carbon compounds?
Which experiment demonstrated evidence for the origin of carbon compounds?
Which organic molecules can spontaneously form spherical bilayers, potentially encapsulating self-replicating molecules?
Which organic molecules can spontaneously form spherical bilayers, potentially encapsulating self-replicating molecules?
What is considered to be the smallest unit of life on Earth?
What is considered to be the smallest unit of life on Earth?
Which molecules may have been able to spontaneously form polymers on early Earth via anabolic reactions?
Which molecules may have been able to spontaneously form polymers on early Earth via anabolic reactions?
Approximately how long ago is there evidence that life existed on Earth?
Approximately how long ago is there evidence that life existed on Earth?
What is the length of time over which life has been evolving on Earth?
What is the length of time over which life has been evolving on Earth?
Which of the following is NOT mentioned as an approach used to estimate the dates of major events in the evolution of life on Earth?
Which of the following is NOT mentioned as an approach used to estimate the dates of major events in the evolution of life on Earth?
During which event did the oxygen concentration in the Earth's atmosphere increase from 0% to around 20%?
During which event did the oxygen concentration in the Earth's atmosphere increase from 0% to around 20%?
When did photosynthesis first evolve?
When did photosynthesis first evolve?
What changes did photosynthesis cause to the Earth's atmosphere?
What changes did photosynthesis cause to the Earth's atmosphere?
