Life on our planet absolutely depends on photosynthesis, on the one hand, 98% of the oxygene comes from this process; fuel molecules contain carbon, from which all living beings on the Earth nourish.
Clorophyle, the main pigment in photosynthesis, absorbs violet, blue, and red wavelengths, and it is green because it reflects that specific type of light.
Animals need of others to obtain energy from food. However, there are others, such as sea slugs that produce their own energy through photosynthesis. They eat algae, but do not digest them completely, and whatever remains in their system continues performing photosynthesis, feeding the slug just the way plants do.