Answer :
the plant has to need something from the animal and the animals to need something from the plant.
Answer: The plants needs something from animals and the animals needs something from plants.
Explanation:
The word interdependent means that the both plants and animals depends on each other for something.
The plants needs carbon dioxide from the animals to synthesize food. This food can be used by the animals in order to get energy from the food.
The Exchange of materials should take place in between the plants and animals to maintain interdependency.