B.13A-Interdependence_onlevel – 02

Amira noticed a bee covered with pollen in her garden. She knows that the bee is helping the flowers, but she wonders if other living things have close relationships.

When a honeybee collects nectar from a flower, pollen grains attach to the bee’s back. As a honeybee moves from flower to flower, pollen grains are distributed amongst all the flowers that the honeybee encounters. This relationship between honeybees and flowers is beneficial to the stability of the ecosystem. There are many interactions between species that impact ecological communities in positive and negative ways.

In the example of the flowers and honeybee, both species benefit from the interaction. This symbiotic, or long-term, relationship is referred to as mutualism. The honeybee collects nectar as a food source for the bee colony. The pollen that is introduced into another flower is now available to fertilize the eggs of the flowers. This process allows for the continuation of the reproductive cycle of the flower. Both species benefit from this mutualistic relationship. The ecosystem also benefits and continues in an average state. An ecosystem that deviates very little from its average state is considered stable. Mutualism helps to maintain the stability of an ecological community.

An excellent example of mutualism is the relationship that many animals – from termites to humans – have with microorganisms that reside in their gut. The microorganisms reside in a safe, hospitable environment in the digestive tract of the animal. The microorganisms receive a steady supply of nutrients from the food that the animal ingests. In the process, microbes break down the larger nutrient molecules into smaller molecules. The smaller molecules, such as sugars and fatty acids, are more easily digestible by the animals. This is a very important step in the cycling of nutrients through an ecosystem and helps maintain ecosystem stability.