Chapter 2.2, Problem 6MI

Summary Introduction

To design:

The three-step example of the flow of energy.

Introduction:

The flow of energy in the ecosystem is an essential factor for the survival of organisms. The energy flows through the trophic levels. The source of energy on earth is the sun. The sun’s solar energy is used by autotrophs (green plants) to make food in the form of chemical energy. All other animals directly or indirectly depend on plants for the supply of energy.

Explanation of Solution

In a food chain, energy flows from producer( consumers ( decomposers:

Autotrophs: Self-feeders and producers.

They make their food using sunlight in photosynthesis. Examples are green plants (land) and algae in the water.

Heterotrophs:

They are consumers. They may be herbivores, carnivores, omnivores or scavengers.

They depend for food on autotrophs and other heterotrophs or both. The organisms that are eaten release energy and molecules for the consumer’s body. Examples are all class of animals.

Decomposers:

They obtain food by breaking down dead or decaying organisms. The decomposed body release energy and molecules for the decomposers. Examples are fungi and bacteria.

Conclusion

The flow of energy in an ecosystem is unidirectional. The ultimate source of energy is the Sun. Solar energy from the sun is fixed by autotrophs (producers), from producer energy moves to the different consumers and then on their death energy moves to decomposers.