Foot Chain

Ecology is the branch of biology. It deals with the relationship between a living thing and another living thing. It also deals with the relationship between a living thing and its environment. The scientists in ecology are called ecologists. Ecologists study the activities and changes in the natural world. It includes the relation between the biological environment and the physical environment. The relation between the two environments forms an ecosystem. The series of energy changes in the form of food is called a food chain.
The food chain starts with the sun. Sunlight provides energy. This energy is needed by the primary producers, such as a grass, and other green plants. They grass is eaten by the primary consumer, such as a mouse, or a deer. Then, the secondary consumer eats the mouse. The secondary consumer, such as a snake, is eaten by the third consumer, such as a hawk. When the last animal in the food chain dies, it is decomposed by the decomposers, such as bacteria or fungi. The decomposer changes the dead body into simple nutrients. The simple nutrients go back into the soil. They are used again by the plants.