Question

How does the appearance of photosynthetic plants relate to the increase in atmospheric oxygen and the decrease in carbon dioxide

Answer 1

Photosynthetic plants use carbon dioxide to generate and function. Plants need energy (glucose) to survive. They exist to absorb carbon dioxide from the atmosphere. One of their end products is oxygen. Animals take in oxygen and release carbon dioxide while the plants take in carbon dioxide and release oxygen. This is balance. 

Answer 2

Answer:

They need to make glucose to survive so that produces oxygen.