Question

models of energy flow contrast a food chain with a food web. state three things that an ecological pyramid shows that food webs and food chains do not show. create a food web and name the organisms you include. indicate each organisms trophic level.

Explanation:

1. A food - chain is a linear sequence of organisms where each is eaten by the next one in the chain. A food - web is a complex network of interconnected food - chains, showing multiple feeding relationships among organisms.
2. An ecological pyramid shows the relative amount of energy, biomass, or number of organisms at each trophic level. Food - webs and chains do not directly show these quantitative relationships in a hierarchical way.
3. For creating a food - web: Consider a grassland ecosystem. Grass (producer, first trophic level) is eaten by grasshoppers (primary consumer, second trophic level). Grasshoppers are eaten by frogs (secondary consumer, third trophic level) and mice (secondary consumer, third trophic level). Mice are also eaten by snakes (tertiary consumer, fourth trophic level) and hawks (tertiary consumer, fourth trophic level).

Answer:

1. A food - chain is linear; a food - web is a network.
2. Energy amount at trophic levels, biomass at trophic levels, number of organisms at trophic levels.
3. Grass (producer, 1st trophic level), grasshopper (primary consumer, 2nd trophic level), frog (secondary consumer, 3rd trophic level), mouse (secondary consumer, 3rd trophic level), snake (tertiary consumer, 4th trophic level), hawk (tertiary consumer, 4th trophic level)