The $\underline{\text{primary}}$ Source of Oxygen for Earth's Atmosphere During the Past Half

question 34

Multiple Choice

The $\underline{\text{primary}}$ source of oxygen for Earth's atmosphere during the past half billion years or so appears to be

• A)volcanic eruptions.
• B)photosynthesis.
• C)​radiant heat.
• D)​exhalations of animal life.
• E)​transpiration.

---

Definitions:

Dendrites

The branched extensions of a neuron that receive signals from other neurons.

Insulate Neurons

The process of covering neurons with myelin, a fatty substance that speeds up the transmission of electrical signals along nerve cells.

Integrate Information

The process of combining data from different sources and making sense of it, often to form a comprehensive understanding or to make decisions.

Conduct Information

The process or manner in which data or knowledge is transmitted or conveyed.