Who's Eating What?
A caterpillar eats only plant leaves. This is its consumer classification.
What is an herbivore?
In the model grass → cricket, the arrow shows this moving from the grass to the cricket.
What is energy or matter?
Before becoming chemical energy in a sunflower, most of its incoming energy was in this form.
What is light energy from the sun?
A researcher counts grasses, grasshoppers, and frogs at each trophic level. This pyramid displays those counts.
What is a pyramid of numbers?
A seedling uses absorbed materials to build new roots and leaves. Those new tissues add to this measure of its organic material.
What is biomass?
An owl eats mice and other animals. This is its consumer classification.
What is a carnivore?
This model follows one feeding pathway, while a food web connects many feeding pathways.
What is a food chain?
Producers contain 8,000 J of energy. At 10% transfer, this much reaches primary consumers.
What is 800 J?
A researcher measures the total dry mass at each trophic level in grams per square meter. This pyramid displays those measurements.
What is a biomass pyramid?
Fungi break down a fallen log. Explain how this can help nearby plants grow.
What is decomposition returns nutrients to the environment that plants can absorb and use?
A beetle eats dead leaves on the forest floor. This feeding role describes an organism that eats dead organic matter.
What is a detritivore?
In algae → snail → fish → heron, the fish occupies this numbered trophic level.
What is the third trophic level?
Primary consumers contain 600 J of energy. Using the lesson’s 5–20% transfer range, this is the range available to secondary consumers.
What is 30–120 J?
Of producers, primary consumers, and secondary consumers, this group forms the widest level of an energy pyramid.
What are producers?
In pond plants → snails → fish, disease greatly reduces the plants. Predict a likely effect on both consumer populations if alternative food is limited.
What is snails would likely decline as food decreases, followed by a decline in fish as fewer snails are available?
A rabbit and a fox have different diets, but both belong to this broad group because they obtain energy by eating other organisms.
What are consumers?
Construct a four-organism food chain using these feeding facts: a snake eats a frog, a grasshopper eats grass, and a frog eats a grasshopper.
What is grass → grasshopper → frog → snake?
An insect consumes 900 J of food energy. It loses 350 J in waste and uses 460 J in metabolism, ultimately released as heat. This much remains for new biomass.
What is 90 J?
One large tree supports hundreds of plant-eating insects. Explain why the producer level can be narrower than the primary-consumer level in a pyramid of numbers.
What is one large producer can support many small consumers, and the model counts individuals rather than measuring their size or mass?
A student says energy is destroyed when an animal releases heat. Correct the statement.
What is energy is conserved; it changes form and disperses into the environment, leaving less available for the next trophic level?
A bird eats seeds during one meal and plant-eating insects during another. Identify its consumer classification and its role in each meal.
What is an omnivore that acts as a primary consumer when eating seeds and a secondary consumer when eating the insects?
A hawk eats both seed-eating mice and lizards that eat plant-eating insects. Identify the hawk’s consumer role in each pathway.
What is a secondary consumer when eating the mice and a tertiary consumer when eating the lizards?
Producers contain 40,000 J. Assuming 10% transfer at each step, this much reaches tertiary consumers. Show the transfers.
What is 40 J?
40,000 → 4,000 → 400 → 40 J.
A student claims an energy pyramid and a biomass pyramid show identical information. Identify what each measures and give an appropriate unit for each.
What is available energy, measured in joules or kilocalories, versus dry mass, measured in grams per square meter?
A sealed terrarium can reuse matter, but it still needs an outside energy source. Explain why.
What is matter cycles through organisms and the environment, while energy flows through the system and eventually leaves as heat, so a continuing energy input is needed?