A food web demonstrates the nutritional relationships in an ecosystem. Obviously, if an organism consumes only one food source, if that food became scarce or if it were completely depleted, the organism would starve and the species would die off. In nature, usually, there are many foods a heterotroph can consume. For instance, a snake might eat a frog, a mouse or a rabbit. The greater the biodiversity, the healthier the ecosystem is. All living things--plants and animals are interdependent. Unfortunately for the Panda bear, its only food is bamboo. Because the bamboo forests are being cut down, this organism may ultimately face extinction.
Animals, like people, need a variety of food sources in order to be healthy. This variety in their diet provides the animal's body access to a broader range of vitamins and minerals, fiber and protein. This enables their bodies to perform correctly. The more an animal's - or person's - diet is restricted, the more likely they are to become ill or even malnurished, because their bodily functions are unable to perform properly.