Answer:
In the case of the cow and the grass, living things depend on each other in a mutualistic relationship:
Cow depends on grass: The cow is a herbivore that depends on grass as its primary source of food. Grass provides the cow with nutrients, energy, and essential substances like carbohydrates, proteins, and vitamins necessary for its growth, survival, and reproduction. Without grass, the cow would not have an adequate food supply and would struggle to survive.
Grass depends on the cow: In a process known as grazing, the cow consumes the grass. As the cow grazes, it trims the grass, stimulating its growth. The act of grazing promotes new shoots and encourages the grass to become more vigorous and resilient. Additionally, the cow's digestive system breaks down the grass, releasing nutrients through feces, which serve as natural fertilizer for the soil. These nutrients, such as nitrogen, phosphorus, and potassium, benefit the grass and enhance its growth.