Answer:
Hello!
Here's the correct order of events:
- Development of photosynthesis
- Free oxygen in the atmosphere
- Development of eukaryotic cells
- Sexual reproduction
Explanation:
Development of Photosynthesis:
3.5 billion years ago, the first photosynthetic bacteria emerged. They used near infrared light to form sulfates or sulfur compounds instead of oxygen.
Free oxygen in the Atmosphere:
Later, about 2.7 billion years ago, cyanobacteria or blue-green algae began to perform oxygenic photosynthesis by utilizing visible light.
Development of Eukaryotic Cells:
The first eukaryotic cell probably appeared around 2 billion years ago. The evolution of eukaryotes is explained by the endosymbiont theory. The endosymbiotic theory explains that eukaryotic cells formed when an ameoba like organism engulfed cyanobacteria and a microorganism capable of cellular respiration that later evolved into chloroplasts and mitochondria respectively.
Sexual reproduction:
The origins of sexual reproduction are still widely debated upon; some studies claim the event occurred 1.2-2 billion years ago.
