Respuesta :
Answer: The surface of early earth was mostly molten and volcanic. The atmosphere was hot and highly toxic.
Explanation: Photosynthetic organisms were present when earth was primarily anoxic. photosynthetic organisms were present when earth was primarily anoxic. the early forms of photosynthesis did not produce oxygen as a waste product. cyanobacteria carry out anoxic photosynthesis. the early forms of photosynthesis did produce oxygen, but it was not enough to make a difference in the atmosphere. the early forms of photosynthesis were carried out in the water, and there was no way for the oxygen to move into the atmosphere.
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Early earth have been toxic for modern day animals as at that time atmosphere is oxygen free, and cyanobacteris is able to survive due to symbiosis.
What are cyanobacterias?
Cyanobacteria is a group of microorganisms that are related to bacteria but can perform photosynthesis. They are prokaryotic and are thought to be the earliest form of life on the planet.
Early earth atmosphere may proof toxic for modern day animals because at the earliest time, atmosphere is oxygen free means no oxygen is present in the atmosphere. And in the today scenario we can't imagine life without oxygen.
Cyanobacteria were able to suvive in that early atmosphere through alternative option like symbiosis in which a cell merges with another cell in order to the survival of both cells.
Hence life is toxic at the early time because of the absence of oxygen.
To know more about cyanobacteria, visit the below link:
https://brainly.com/question/1516890
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