The diagram below shows a food chain. Use the model to explain how these four organisms received the food matter they need to create the biomolecules for food and growth. Explain why the tree is at the beginning of the model and the bird is at the end using the concepts you’ve learned in this unit.

Answer 1

In a food chain, organisms are arranged according to their feeding relationships, illustrating how energy and nutrients flow through an ecosystem. Typically, this chain begins with producers and ends with consumers. In this case, we have a tree, a herbivore, a carnivore, and a bird. Here's how they receive food matter for growth and the reasons for their positions in the food chain.

1. Tree (Producer): The tree is at the beginning of the food chain as it is a primary producer. It utilizes photosynthesis to convert sunlight into chemical energy, producing organic compounds (biomolecules) such as carbohydrates, proteins, and fats from carbon dioxide and water. These biomolecules are crucial for the tree’s growth, reproduction, and maintenance. The tree serves as the foundational source of energy within this ecosystem.

2. Herbivore (Primary Consumer): The herbivore feeds directly on the tree. By consuming the leaves, fruits, or other parts of the tree, the herbivore takes in the stored energy and biomolecules created by the tree. This allows the herbivore to grow and develop its own biomolecules while also providing energy for its bodily functions. The herbivore is a primary consumer as it directly relies on the producer.

3. Carnivore (Secondary Consumer): The carnivore preys on the herbivore, obtaining energy and nutrients necessary for its growth. By consuming the herbivore, the carnivore assimilates the biomolecules that were originally derived from the tree. The transfer of energy and nutrients from the herbivore to the carnivore happens at a higher trophic level.

4. Bird (Tertiary Consumer): Finally, the bird, which is a tertiary consumer, feeds on the carnivore. In this step, the bird gains energy and biomolecules by consuming the carnivore, which indirectly consumed the herbivore. Each step in this food chain represents a transfer of energy, with the bird at the highest level because it is at the top of this particular food chain.

Conclusion: The tree is at the beginning of the food chain because it synthesizes its own food and serves as the primary source of energy for the ecosystem. As a producer, it supports all other organisms in this chain. The bird is at the end of the model as it is the top consumer, relying on multiple levels of transfer before obtaining its food. Each organism plays a crucial role in the ecosystem as energy is passed from one trophic level to the next, with energy loss occurring at each transfer due to metabolic processes, heat, and other factors. This reflects the fundamental concepts of energy flow and trophic levels within an ecological model.