Question

Which of the following would have resulted from the functions of prokaryotes on early Earth? Earth's oceans grew larger less oxygen gas became present in the atmosphere less carbon became present in Earth's soil more oxygen gas became present in the atmosphere

Answer 1

more oxygen gas became present in the atmosphere'

Answer 2

The correct answer is 'more oxygen gas became present in the atmosphere'. Early prokaryotes were photosynthetic organisms; they used energy from the sun along with carbon dioxide to manufacture food. A known byproduct of this reaction is the release of oxygen. Over millions of years the concentration of oxygen built up in the atmosphere. Cyanobacteria are examples of such organisms.