Trophic Level Worksheet

Press Print worksheet to match twelve trophic level terms, from producer to apex predator, to their meanings.

A sample is on the sheet. What you type replaces it.

What you type stays in your browser. Nothing is sent to us.

NameDateMade at homeroomtools.comDraw a line from each one on the left to its partner on the right.Trophic levels vocabularytrophic levelproducerprimary consumersecondary consumertertiary consumerdecomposerfood chainfood webenergy pyramidapex predatorherbivorecarnivorea diagram of the energy held ateach trophic levela hunter at the top, with nohunters of its owna row of living things, each onefood for the nexta fungus or microbe that rotsremains into nutrientsthe second eater in a chain: iteats plant eatersthe first link: it builds its foodwithout eatingone step of a food chain, countedfrom its starta meat eater, whether it hunts orscavengesall the food chains of one place,joined togetheran animal that lives on leaves,seeds, fruit or algaethe third eater in a chain, ontrophic level fourthe first eater in a chain, ontrophic level two
NameDateMade at homeroomtools.comDraw a line from each one on the left to its partner on the right.Trophic levels vocabularyAnswer keytrophic levelproducerprimary consumersecondary consumertertiary consumerdecomposerfood chainfood webenergy pyramidapex predatorherbivorecarnivorea diagram of the energy held ateach trophic levela hunter at the top, with nohunters of its owna row of living things, each onefood for the nexta fungus or microbe that rotsremains into nutrientsthe second eater in a chain: iteats plant eatersthe first link: it builds its foodwithout eatingone step of a food chain, countedfrom its starta meat eater, whether it hunts orscavengesall the food chains of one place,joined togetheran animal that lives on leaves,seeds, fruit or algaethe third eater in a chain, ontrophic level fourthe first eater in a chain, ontrophic level two
More options

Next step Next: ecosystem word search

All 36 terms

Trophic levels 12

  • apex predator A hunter at the top, with no hunters of its own. Orcas and great white sharks are apex predators.
  • carnivore A meat eater, whether it hunts or scavenges. The word joins the Latin for meat with the Latin for to devour.
  • decomposer A fungus or microbe that rots remains into nutrients. They break dead organisms down, and the nutrients go back into the surroundings.
  • energy pyramid A diagram of the energy held at each trophic level. It is always widest at the bottom, where the producers are.
  • food chain A row of living things, each one food for the next. Grass or algae is often the first link, and an apex predator is often the last.
  • food web All the food chains of one place, joined together. It shows what eats what across a whole community.
  • herbivore An animal that lives on leaves, seeds, fruit or algae. In the sea, herbivores eat algae and phytoplankton.
  • primary consumer The first eater in a chain, on trophic level two. It eats producers. Every herbivore is a primary consumer.
  • producer The first link: it builds its food without eating. Plants and algae are producers. They are the first trophic level, the base of the food web.
  • secondary consumer The second eater in a chain: it eats plant eaters. A carnivore that eats herbivores is a secondary consumer.
  • tertiary consumer The third eater in a chain, on trophic level four. It eats secondary consumers. In one ocean food web, tuna and seals are tertiary consumers.
  • trophic level One step of a food chain, counted from its start. Producers are level 1, plant eaters level 2 and meat eaters level 3 or higher.
Show all 36 terms (24 more)

Who eats what 12

  • arrow In a food chain drawing, it points from food to eater. It shows which way the energy goes: an arrow from plankton to krill means that krill eat plankton.
  • autotroph A self-feeder: the formal term for a producer. Phytoplankton are autotrophs, and so are trees.
  • chemosynthesis Food-making powered by chemicals where no light comes. Some bacteria do it with chemicals that come out of hydrothermal vents.
  • consumer Any organism that must feed on others to get energy. Consumers are sorted by what they eat: herbivores, carnivores and omnivores.
  • detritivore An animal that eats scraps of dead, rotting matter. Earthworms and woodlice are detritivores.
  • filter feeder An animal that sieves floating bits of food to eat. Its food is small living things and bits of matter floating in the water.
  • grazer A herbivore that feeds on low plants or on algae. Grazers come in every size, from hippopotamuses to small water snails.
  • heterotroph The science word for any consumer or decomposer. The word joins the Greek for other and for nourishment: it cannot make its own food.
  • link The tie between an eater and the thing it eats. The length of a food chain is counted in links.
  • omnivore An animal with a mixed diet of plant and animal food. Crabs and sea turtles are omnivores.
  • organism One individual plant, animal, fungus or microbe. Any living thing is an organism.
  • plankton Living things carried along by the water they float in. The name is from the Greek for drifter. Phytoplankton and zooplankton are its two main kinds.

Energy and pyramids 12

  • bioaccumulation The slow buildup of a substance inside one organism. It happens when a living thing takes a substance in faster than it can get rid of it.
  • biomagnification A substance building up more at each higher level. Mercury can build up to high levels in tuna, swordfish and other predators at the top.
  • chemical energy The energy stored in food and in living tissue. A consumer turns about a tenth of the chemical energy in its food into its own tissue.
  • ecological efficiency The share of energy handed on from level to level. It is usually low, which is why a food chain seldom runs past five levels.
  • energy flow The passing of energy from one living thing to another. It goes one way and does not return. In most food webs it starts with the sun.
  • keystone species A species with an outsized effect on where it lives. The sea otter is a keystone species of the kelp forest.
  • nutrient cycle The reuse of matter, over and over, by living things. Carbon, nitrogen and water all move in cycles. Energy does not: it flows one way.
  • primary production The making of food from carbon dioxide by producers. Most of it is done by photosynthesis, with light as the source of energy.
  • pyramid of biomass A diagram of the mass of living things on each level. Each bar shows how much living matter that level holds.
  • pyramid of numbers A diagram of how many organisms are on each level. It is one of three kinds of ecological pyramid.
  • ten percent law Only about a tenth of the energy reaches the next level. It is an average: the real share runs from about 5 to 20 percent.
  • trophic cascade A change at the top that ripples down a food web. When sea otters were hunted, sea urchins multiplied and ate down the kelp forests.

How this list was compiled: Term list chosen for this site on 2026-10-11. Each meaning is written in our own words and was checked that day against the English Wikipedia article on the term (https://en.wikipedia.org/), whose text is under the Creative Commons Attribution-ShareAlike license: Trophic level, Consumer (food chain), Decomposer, Food chain, Food web, Ecological pyramid, Apex predator, Herbivore, Carnivore, Omnivore, Autotroph, Heterotroph, Detritivore, Filter feeder, Grazing (behaviour), Plankton, Phytoplankton, Organism, Energy flow (ecology), Nutrient cycle, Bioaccumulation, Ecological efficiency (the ten percent law), Trophic cascade, Keystone species, Biomagnification, Food energy and Primary production. The levels, the producers and consumers, the kinds of feeder, the arrows of a food web, chemosynthesis, the trophic cascade and biomagnification were checked a second time against Aquatic food webs and its glossary, of the U.S. National Oceanic and Atmospheric Administration (https://www.noaa.gov/education/resource-collections/marine-life/aquatic-food-webs). The fact after each meaning is from the same pages. Licence: own work

How it works

On this trophic level worksheet a class matches producer, primary consumer, secondary consumer, decomposer, energy pyramid and seven more terms to their meanings. A key is printed after it. No food web or pyramid is drawn on the sheet.

Read the full guide

Who eats what

Set opens on Trophic levels. Who eats what prints consumer, omnivore, autotroph, heterotroph, detritivore, filter feeder, grazer, plankton, link, arrow, chemosynthesis and organism.

Energy and pyramids

The third set follows the energy: energy flow, ten percent law, ecological efficiency, chemical energy, primary production, pyramid of numbers, pyramid of biomass, nutrient cycle, trophic cascade, keystone species, bioaccumulation and biomagnification.

  • Predator, prey, scavenger and ecosystem are left to the ecosystem word search.

Questions and answers

What are the trophic levels in order?

Producers are level 1. Primary consumers, which eat producers, are level 2. Secondary consumers are level 3 and tertiary consumers level 4. Apex predators stand at the top, usually on level 4 or 5.

Why does only 10 percent of energy pass to the next trophic level?

Most of the energy a living thing takes in is spent on its own life processes, such as respiration, or is lost in waste and in organisms that die uneaten. On average about a tenth becomes body tissue that the next level can eat.

What is an energy pyramid?

A diagram with one bar for each trophic level, sized by the energy held there, and the producers' bar is always the widest. A pyramid of numbers can be upside down: beetles that feed on forest trees outnumber the trees.

More tools

Show 7 more

Browse Handwriting