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7th grade · Science · Unit 4 of 14

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.

New York State Learning Standards learning standard: MS-LS2-3 · energy flowing through food chains and webs

How we explain it

Children can open this short lesson before they practice.

  1. Producers make food from sunlight. Consumers eat other living things. Decomposers break down dead matter.
  2. Arrows in a food chain point from the food to the eater.
  3. Only about 10% of the energy at one level passes to the next.

Example: Plants store 1000 units of energy. About how much reaches the rabbits that eat them? About 10% passes on. 10% of 1000 is 100. Answer: 100 units

Food Chains & Energy in New York

In the New York State Learning Standards, this is unit 4 of 14 in 7th 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: New York State Education Department (NYSED)

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    Sea otters eat sea urchins, and urchins eat kelp. What can happen if the otters are removed from a coast?

    • Urchins increase and the kelp forest can shrink
    • Urchins disappear
    • Kelp grows faster and covers the coast
    • The otters become producers

  2. Question 2

    Put this food chain in order, from the organism that makes food to the last to eat.

    • 🐍snake
    • 🌾grass
    • 🦗grasshopper
    • 🦅hawk

  3. Question 3

    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 grasshoppers that eat the grass?

    answer boxunits

  4. Question 4

    What do producers do?

    • Hunt for food
    • Make their own food using energy from the Sun
    • Eat other organisms
    • Break down dead matter

  5. Question 5

    What do decomposers do?

    • Break down dead organisms and wastes, returning nutrients to the soil
    • Make food from sunlight
    • Store energy as fat for winter
    • Hunt live prey

  6. Question 6

    In a food chain, which organism has the smallest amount of available energy?

    • the top consumer
    • the producer
    • the Sun
    • the primary consumer

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