If Early Earth's Atmosphere Contained Little or No O₂, Then

question 60

Multiple Choice

If early Earth's atmosphere contained little or no O₂, then where did most of the O₂ in our modern atmosphere come from?

• A) Respiration
• B) The oxidation of metals
• C) Photosynthesis
• D) The breakdown of carbon dioxide
• E) The splitting of water vapor by sunlight

---

Definitions:

Populism

A political approach that strives to appeal to ordinary people who feel that their concerns are disregarded by established elite groups.

Communitarianism

A social philosophy emphasizing the importance of community in the functioning of political life, often valuing community goals over individual ones.

Equality of Condition

A social state in which people have the same status in certain respects, including civil rights, freedom of speech, property rights, and equal access to social goods and services.

Equality of Opportunity

The principle that all individuals should have an equal chance to pursue their own goals and interests, typically referring to non-discrimination in access to education, employment, and other resources.