The first multicellular eukaryotic organisms to use the oxygen on Earth were _____.

Question

Quizplus · Accepted Answer

The first multicellular eukaryotic organisms to use the oxygen on Earth were green algae, as they evolved to use photosynthesis to convert sunlight and carbon dioxide into energy and oxygen. This process eventually led to the oxygenation of the Earth's atmosphere, which allowed for the evolution of more complex life forms. Jellyfish, amphibians, Tiktaaliks, and humans all evolved much later than green algae and therefore could not have been the first multicellular eukaryotes to use oxygen.

The First Multicellular Eukaryotic Organisms to Use the Oxygen on Earth