Predators have to eat. If things are good in an eco-system then the prey is eating good which means the predators can eat good also. Starvation means that things in the eco-system are going bad. Also, It helps the earth maintain its balance. If too much of any aspect of the system is removed it throws the whole thing off balance. too many herbivores will eat too much vegetation.
Sidney W. Fox produced proteinoid spheres, which suggest a possible route from chemical to cellular life.
Cellular respiration and photosynthesis both have water and carbon dioxide in their reactions.
Photosynthesis contributes to plant growth by B. taking in carbon dioxide and making sugars (carbohydrates)