Answer:
D. a city that is the largest and most influential in its region
Answer:
b. Bacteria photosynthesizing dissolved carbon dioxide in oceans
Explanation:
The levels of oxygen that we know nowadays in the atmosphere have not been like this in the more distant past. In order for the oxygen to start building up and change the composition of the atmosphere, something needed to happen, and that something was the cyanobaceteria. The cyanobacteria was able to perform photosynthesis, so it started to use the dissolved carbon for it, while in meantime it was releasing oxygen in the atmosphere. As the cynaobacteria was growing in numbers, over the course of millions of years, it managed to propel enough oxygen in the atmosphere so that the other organism can start developing, thus changing the world forever.
The earliest event enabling oxygen production in Earth's atmosphere was cyanobacteria, also known as blue-green algae, photosynthesizing dissolved carbon dioxide in oceans and releasing oxygen as a byproduct.
The earliest event that allowed for the production of oxygen in Earth's atmosphere was b. Bacteria photosynthesizing dissolved carbon dioxide in oceans.
During the first two billion years of Earth's existence, the atmosphere was anoxic - it lacked molecular oxygen. The only living organisms were anaerobic organisms, which can survive without oxygen. The process began to change with the appearance of phototrophs, autotrophic organisms which convert solar energy into chemical energy, and later cyanobacteria or blue-green algae evolved from these simple phototrophs.
Cyanobacteria began the oxygenation of the atmosphere by undertaking photosynthesis and releasing oxygen as a by-product. Their emergence and the resulting increase in atmospheric oxygen allowed for the development of more complex life forms, and the colonization of land, as the ozone layer (formed from oxygen) could absorb harmful ultraviolet light.
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B) subduction causes oceanic crust to break into pieces
C) Subduction causes the ocean floor to sink into deep ocean trenches
D) subduction causes metamorphic rocks to form
Answer:
plateaus are mountains but they just are uplifted and flat mountains are uplifted but they are not necessarily flat what other mountain landforms do you want.
Explanation: