Why do plants and animals depend on each other to survive?
Plants rely on animals so they can grow and as you can see here this "bee" is giving the flower pollen which is helping it grow.
The sun is giving the tree energy which is then created into rich sugar molecules and the sugar is now available for the animals to eat.
As you can see they need each other for the food and for growth and energy because the animal gives the flower pollen and tree gives the animals sugars so they can eat on. Without this they would most likely not survive.