Answer :
1. The first types of organisms that developed on early Earth were simple, single-celled prokaryotic organisms like bacteria. These organisms were among the earliest forms of life on our planet.
2. These prokaryotic organisms developed first because they were able to thrive in the harsh conditions of the early Earth, which lacked oxygen and had high levels of volcanic activity. Prokaryotes were able to use various energy sources available in that environment, such as chemicals from volcanic vents, to sustain themselves.
3. Sequence showing the appearance of living organisms on Earth:
1. Prokaryotic organisms (bacteria)
2. Cyanobacteria (photosynthetic bacteria)
3. Eukaryotic organisms (cells with a nucleus)
4. Multicellular organisms
4. The event that contributed most directly to the rise of aerobic organisms on Earth was the Great Oxygenation Event (GOE). This event, which occurred around 2.4 billion years ago, involved the significant increase in atmospheric oxygen due to the photosynthetic activity of cyanobacteria. The rise in oxygen levels created an environment conducive to the evolution of aerobic organisms that could use oxygen for respiration, leading to the diversification of life on Earth.
