6th Grade · Science · Reading Passage · shared by Luke Morgan
Discover a 6th Grade Science reading passage on Prochlorococcus, photosynthesis, and ocean oxygen production. Access free K-12 material.
The Tiny Breath of the Ocean
Every single breath you take connects you to the vast and mysterious blue waters of the global ocean. While many people believe that tall trees in rainforests provide all our air, tiny organisms actually do much more. One important creature on our planet is a microscopic living thing called Prochlorococcus . This tiny cell is so small that millions of them can fit inside a single drop of salty seawater. Despite their miniature size, these organisms are the most abundant photosynthetic creatures found anywhere on the entire Earth today. They play a massive role in keeping our atmosphere healthy by producing the oxygen that humans need to survive.
This organism belongs to a group of ancient life forms known as cyanobacteria , which are types of bacteria that make food from sunlight. They are found in the warm, sunlit layers of the ocean where they drift peacefully with the moving currents. Because they are small, scientists did not know they existed until the late 1980s. They lack the complex structures found in land plants, yet they are perfectly designed for their watery home. Their simple design allows them to thrive in nutrient-poor areas where other larger marine plants might struggle to grow.
The secret to their success lies in a special process called photosynthesis , which transforms light energy into chemical energy. Just like garden plants, these tiny cells use sunlight, water, and carbon dioxide to create sugar for their growth. As a natural byproduct of this amazing chemical reaction, the cells release pure oxygen back into the surrounding water. Eventually, this oxygen moves from the ocean surface into the air, where it becomes part of the atmosphere we breathe. Scientists estimate that these tiny green cells are responsible for…