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4th grade · Science · Unit 17 of 17

Food Webs & Decomposers

How matter and energy move from the Sun through producers, consumers and decomposers.

What your child practices

Practices how matter cycles and energy flows through food webs, including the roles of the Sun, producers, consumers and decomposers, with Texas examples such as prairie grasses, jackrabbits and coyotes.

Texas Essential Knowledge and Skills (TEKS) teks student expectation: 4.12(B) · matter cycling and energy flow through food webs, including producers, consumers and decomposers

How we explain it

Children can open this short lesson before they practice.

  1. Energy flows from the Sun to producers (plants), then to consumers.
  2. Decomposers, like fungi, bacteria and some insects, break down dead things.
  3. Decomposers return nutrients to the soil for plants to use.
  4. If a predator disappears, its prey usually increases.

Example: In grass → grasshopper → bird, which consumer eats the producer? Grass is the producer. The grasshopper eats the grass. Answer: the grasshopper

Food Webs & Decomposers in Texas

In the Texas Essential Knowledge and Skills (TEKS), this is unit 17 of 17 in 4th grade Science, after Weathering, Erosion & Fossils.

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: Texas Education Agency (TEA)

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

    What would happen without decomposers?

    • Plants would grow better
    • Nothing would change
    • Animals would live forever
    • Dead things would pile up

  2. Question 2

    Organisms that break down dead things are…

    • predators
    • producers
    • decomposers
    • herbivores

  3. Question 3

    The energy in almost every food web starts with…

    • the Sun
    • the soil
    • decomposers
    • top predators

  4. Question 4

    A red-tailed hawk eats snakes and mice. In a food web it is a…

    • nonliving part
    • producer
    • decomposer
    • consumer

  5. Question 5

    Plants take in matter from the air and…

    • water from the soil
    • rocks
    • metal
    • sunlight as matter

  6. Question 6

    After salmon spawn and die, their bodies…

    • vanish
    • feed the forest and river life
    • swim to the ocean
    • turn to stone

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