Answer:
Grass, deer, wolf, fungi.
Explanation:
The tropical level of an organism is defined as the position of organism occupied in the food chain. The food chain is starts from tropical level one which is primary producers (such as plants), then move to herbivores (such as deer) in level two, carnivores, (such as wolf) at level three, apex predators in level four (such as lions), and it ends in decomposers such as fungi.
Fungi play important role in ecosystem to help in breakdown of dead organic matter and return nutrients to the soil. Without fungi nutrients cannot cycle in an ecosystem, and causing the breakdown of entire food web.
