Question

Algae gives 60% of oxygen. How?

Answer 1

About 75 % of the world's atmospheric oxygen is produced by phytoplankton in the global oceans, In other words, Algae. Similar to plants, Algae do photosynthesis(a process through which green plants convert carbondioxide into energy in the presence of sunlight and chlorophyll(which is the chemical responsible for green colour in plants), and oxygenn is the byproduct). As the amount of these algae is high, the amount of oxygen produces is alo high, higher even than that contributed by the entire plants in the world. So that is why it is about 60% .
For more details on photosynthesis, refer Byju's