What role did cyanobacteria play in the cambrian explosion? quizet?

Cyanobacteria, also known as "blue-green algae", are the unicellular organisms which are able to produce oxygen.

Approximately 540 years ago, the atmosphere was very poor on oxygen. Cyanobacteria are thought to be responsible for the oxidization of the atmosphere back then, in an event known as "The Great Oxygenation Event". As a result, Earth's life forms suffered drastic changes in their composition, as they evolved from being anaerobic to becoming organisms highly dependant on oxygen. The oxygenation of the atmosphere would eventually provide the adequate environment in order for the Cambrian Explosion, or the first diversification of living organisms, to happen.  

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the president, prime minister, chief justice, speakers and ministers take their oath of office. the oath is taken in bengali

no

explanation:

not everyone in america is free. it is has always been a unequal society. and yet people come in swarms, in search of better lives. some are brought as children, unaware, unknowing. some arrive and just don’t leave. they build lives, pay taxes, raise families. some enter illegally, fleeing persecution in their home country.

there are many reasons why human beings are so attracted to america, despite its history of bitterness towards immigrants.

there are almost two million immigrants brought to the us when they were children. president donald trump and his collaborators are determined to rid the us of as many undocumented immigrants as they can, and stop others from coming because none of their ancestors were immigrants.

america has so many things and yet it lacks the one thing that humanity needs to fully thrive. and so this country will not be at peace in itself until it resolves the pain at the heart of slavery, attacking immigrants, and crumble the rights of those with less power.