Final answer:
Energy in a food web begins with sunlight, which plants convert into chemical energy through photosynthesis. This energy flows through ecosystems from plants to herbivores and then to carnivores, with energy lost as heat at each level.
Step-by-step explanation:
The flow of energy in a food web describes the process by which energy is transferred from one organism to another within an ecosystem. The original source of energy is typically sunlight, which is converted into chemical energy by plants through photosynthesis. Plants, or producers, are the primary source of energy for herbivores, or primary consumers, that eat the plants. Energy then flows to carnivores, or secondary and tertiary consumers, that eat the herbivores. After being used by organisms for growth and maintaining life processes, this energy is ultimately lost as heat due to metabolic activities.
In a typical food chain, a food web diagram would depict the energy flow starting from a plant, progressing to a herbivore like a grasshopper, then to a primary carnivore such as a bird, which may in turn be eaten by a secondary carnivore, like a snake, and finally to a tertiary carnivore such as an owl. Since each organism requires energy to survive, the food web illustrates not only who eats whom but also shows the direction of energy transfer through different trophic levels. Ultimately, the web reflects the interconnectedness of the ecosystem, with many intersecting food chains representing complex feeding relationships.
A food web represents multiple pathways through which energy and matter flow through an ecosystem. It includes many intersecting food chains. Energy is acquired by living things in three ways: photosynthesis, chemosynthesis, and the consumption and digestion of other living or previously living organisms by heterotrophs.