The seasons are caused as the Earth, tilted on its axis, travels in a loop around the Sun each year. Summer happens in the hemisphere tilted towards the Sun, and winter happens in the hemisphere tilted away from the Sun. As the Earth travels around the Sun, the hemisphere that is tilted towards or away from the Sun changes.
Answer:
The correct answer is option - C. They replaced carbon dioxide with oxygen in the atmosphere.
Explanation:
Cyanobacteria or Blue-green algae is a group of bacteria that is making its own food using water and carbon dioxide in the presence of sunlight, the process of photosynthesis
These organisms release oxygen as a byproduct of photosynthesis in the atmosphere. Through this process, these organisms replaced carbon dioxide with oxygen in the atmosphere in the early earth.
Thus, the correct answer is option C. They replaced carbon dioxide with oxygen in the atmosphere.
Photosynthesis allows plants, algae and certain bacteria to turn sunlight into chemical energy. The amazing feat is achieved because sunlight can fuel a reaction between water and carbon dioxide that, in turn, produces carbohydrates (simple sugars) and oxygen.
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Because the soil didn't have the same nutrients it has now due to lack of decomposition of other plants and animals.
Hag Fish and Lamprey
Vertebrates are the organism which posses a vertibral column(aka the spine or back bone structure), while the earliest had a head they lacked a spine and jaw, these jawless vertebrae lived 500-600 million years ago. they are the ancestors of bony fish which in time became amphibians and other groups of animals