Earth's early atmosphere had no oxygen. Use your understanding of plant photosynthesis to explain how photosynthetic organisms made the evolution of organisms that use aerobic cellular respiration possible.

Before, microorganisms were anaerobes, so they did not need oxygen to carry out photosynthesis, but with the appearance of cyanobacteria, which are blue-green algae, oxygen began to appear in the atmosphere.

These reactions to oxygen photosynthesis, which was what generated a very abrupt change in the ecosystem, since many prokaryotic microorganisms did not support the presence of this gas in the atmosphere and became extinct, others adapted, others developed oxygen photosynthesis such as these algae

These bacteria work with the respiratory chain mechanism and it was they who transmitted this genetics horizontally to other bacteria as an adaptation and evolution mechanism.

Explanation:

The mechanism of transmitting genetic load in a horizontal direction made it not dependent on the following generations, since genetic load is transmitted by routes such as PILI or other means, some of them call this mechanism the lateral transmission method but refer to the same thing.

In simple words, these bacteria imposed the oxygen photosynthesis and transmitted or spread their genetic load based on the encoding of the respiratory chain, so that other bacteria can perform the same metabolic method and adapt to oxygenated media.

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.