Construction of Food Webs and Food Chains

Construction of Food Webs and Food Chains

Feeding relationships can be shown in a simple way where organisms feed on the next organisms in a liner sequence. This is called a food chain. However, in reality most organisms have several food sources that interact with one another. These interactions can be represented in a food web.

Learning Objectives

To mention the components of a food chain and food web.

Materials

Manila sheet or at boxes, maker pens, specimens or pictures of maize seedlings, termite, toad, caterpillar (butter y/beetle larva), and a small bird

Preparation Procedure

1.           Germinate maize grains to get seedlings.

2.           Ask students to collect and bring in termites, toad, a small bird, and a caterpillar in a cage or plastic bottle.

Activity Procedure

1.           Arrange the 3 organisms on the manilla paper or at box in such away that one organism is the food source for another organism. This feeding relationship should make a line, for example maize, caterpillar, small bird.

2.           Write names of each organism and their tropic level.

3.           Draw arrows on the manilla paper, pointing away from the organism being eaten.

4.           Arrange all the organisms randomly on the other manilla sheet.

5.           Draw arrows away from each organism being eaten towards the organ-isms that is eating it.

6.           Write the names of each organism and their tropic level.

Results and Conclusion

The rst diagram indicates a food chain while the second one indicates a food web. Food chain shows a sequence of living things in which each organism is the food of the next one in the sequence. Arrows are used to show the direction of ow of energy. A food chain starts with the producer and ends with the top consumer.

Clean Up Procedure

1.           Collect all the used materials, cleaning and storing items that will be used later. No special waste disposal is required.

Notes

Primary producers occupy the lowest level in trophic levels. In most cases they are plants. The top consumers occupy the top levels. In this activity birds were the top consumer but in most cases decomposers like bacteria or fungi would be at the top.