6th grade · Science · Unit 8 of 9
Food Chains & Energy
Who eats whom, and the energy
What your child practices
Producers, consumers and decomposers, food chains and webs, how energy shrinks as it passes up a chain (about 10% each step), and what happens when part of a chain changes.
Arizona Academic Standards learning standard: 6.L2U1.14 · the flow of energy through food chains and webs
How we explain it
Children can open this short lesson before they practice.
- The energy in most food chains first comes from the Sun.
- Producers make food. Consumers get energy by eating other organisms.
- Herbivores eat plants, carnivores eat animals and omnivores eat both.
- Arrows show the direction energy flows: from the food to the eater.
Example: In grass → deer → wolf, which way does the energy flow? Arrows point from food to eater. Energy moves from grass to deer to wolf. Answer: from grass to deer to wolf
Food Chains & Energy in Arizona
In the Arizona Academic Standards, this is unit 8 of 9 in 6th grade Science, after Ecosystems and before Cycles & Succession.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Source: Arizona Department of Education
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
Grass stores 1000 units of energy. About 10% of the energy at each feeding level is passed on to the next. How many units reach the frogs that eat the grasshoppers?
answer boxunits
10 units
Hint: Two steps: grass to grasshoppers (divide by 10), then grasshoppers to frogs (divide by 10 again).
Question 2
Only about 10% of the energy passes to the next feeding level. What happens to the rest?
- It disappears for no reason
- Most is used for life processes or lost as heat
- It turns into producers
- It is stored for the next level to use later
Most is used for life processes or lost as heat
Hint: Organisms use energy to move, grow and stay warm, and much leaves as heat.
Question 3
Mushrooms growing on a fallen log are…
- producers
- herbivores
- primary consumers
- decomposers
decomposers
Hint: They break down the dead wood and release nutrients.
Question 4
Put this food chain in order, from the organism that makes food to the last to eat.
- 🦅hawk
- 🐍snake
- 🌾grass
- 🐸frog
grass → frog → snake → hawk
Hint: Energy flows from the producer (grass) to the grasshopper, frog, snake and then hawk.
Question 5
Producer, consumer or decomposer? Sort each organism.
Sort into: 🌿 producer · 🐇 consumer · 🍄 decomposer
- 🦠bacteria in a compost pile
- 🦅a hawk
- 🌾grass
- 🟢algae in a pond
- 🍄a mushroom on a log
- 🐇a rabbit
🌿 producer: grass, algae in a pond · 🐇 consumer: a hawk, a rabbit · 🍄 decomposer: bacteria in a compost pile, a mushroom on a log
Hint: Producers make their own food from sunlight (plants, algae). Consumers eat other living things. Decomposers break down dead matter (many fungi and bacteria).
Question 6
Frogs eat insects, and snakes eat frogs. A chemical spray kills most of the insects. What may happen to the frogs?
- Frog numbers may drop because they have less food
- Frog numbers will definitely rise
- Nothing in the food chain will change
- Snakes will become producers
Frog numbers may drop because they have less food
Hint: Removing the food of one level can affect the levels above it.