The Flow of Energy in Living Things

Integrated Science

Grade 9

Objective: At the end of the reading students will be able to state the main forms of energy with 90% accuracy.

At the end of the reading students will be able to explain how energy flows in living organisms in the environment.

According to Johnson and Hill (2010), energy is defined as the capacity to do work. they continued to state that energy can take many forms which include mechanical, heat, sound, electric current, light or radioactive radiation. Other forms include kinetic, nuclear, potential, chemical, heat and solar.

In the environment, plants convert light energy into chemical energy in the process of photosynthesis. In the food chain, plants are the primary producers which means they make food for other organisms to feed on and survive. The organisms that eat plants are called herbivores. Those who eat animals are carnivores and those that eat both plants and animals are called omnivores. The herbivores are considered as primary consumers because they feed directly on the plants. When the plant is eaten, the chemical energy is converted into different forms so that the organism can do work. The carnivores would be considered as secondary consumers because they would feed on the primary consumers. The omnivores can be considered both primary consumers and secondary consumers.

It is important to note that in the food chain, a plant always starts the chain. When an organism feeds on the other, energy is gained. Interconnected food chains are called food webs.

Below shows a picture of a food chain and a food web.

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