Food Webs & Interdependence · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Food Webs: When Every Chain Connects

Science · Ecosystems & Habitats · ages 11-12
Name ______________________   Date ____________

  1. An apex predator is eaten by many other animals in its food web.

    Circle one:   True   False

  2. In the arrow grass → mouse, which living thing is the food?

    • The mouse
    • The grass
    • Both, they eat each other

  3. In a food web, a fox eats rabbits, mice, and birds. How many different kinds of food does the fox eat?

    Answer: ______________

  4. In a forest food web, which of these is the producer?

    • The deer
    • The mushroom
    • The oak tree

  5. In the web grass to grasshopper to frog to hawk, and grass to grasshopper to sparrow to hawk, if the frog population crashes from disease, what most likely happens to grasshoppers?

    Frogsbefore8Frogsafterdisease2
    • They increase, a predator is gone
    • They decrease, because grass becomes scarce
    • They stay exactly the same

  6. In the chain grass to mouse to snake to hawk, what role does the snake play?

    • primary consumer
    • producer
    • secondary consumer

  7. In a food web, hawks eat frogs, snakes, and sparrows. If the snakes disappear, what most likely happens to the hawks?

    • They all starve, since snakes were their food
    • They can lean on their other foods, frogs and sparrows
    • They become producers and make their own food

  8. Draw this web: grass to rabbit to fox, grass to mouse to fox, and grass to mouse to owl. How many arrows does the finished web have?

    Answer: ______________

  9. A wet spring makes the grass in a meadow grow thick. Grasshoppers eat the grass and frogs eat the grasshoppers. What most likely happens to the grasshoppers and the frogs?

    Grasshoppersbefore3Grasshoppersafter rain7
    • Both tend to increase, since extra food at the bottom supports more life above
    • Both decrease, since tall grass is hard to live in
    • Grasshoppers increase, but frogs must decrease

  10. In a meadow web, snakes eat only mice, and hawks eat snakes, frogs, and sparrows. Disease wipes out most of the mice. What is the most likely knock-on effect?

    Micebefore8Mice afterdisease1
    • Nothing else changes, since only mice were affected
    • The grass disappears, since no mice are left to eat it
    • Snakes decline from hunger, and hawks lean harder on frogs and sparrows
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Food Webs: When Every Chain Connects W1-mt_URTJbS3hhs-s1

  1. False · An apex predator sits at the top. No other animal in the web eats it.
  2. The grass · The arrow starts at the food and points to the eater, so the grass is the food and the mouse is the eater.
  3. 3 · Three arrows lead into the fox, one from each food: rabbits, mice, and birds.
  4. The oak tree · The oak tree makes its own food from sunlight, so it is the producer. The deer eats plants and the mushroom breaks things down.
  5. They increase, a predator is gone · With fewer frogs hunting them, more grasshoppers survive, so their population tends to rise.
  6. secondary consumer · The snake eats the mouse, which is a primary consumer, so the snake is one step further along as a secondary consumer.
  7. They can lean on their other foods, frogs and sparrows · The web gives hawks backup foods, so losing snakes hurts but does not starve them.
  8. 5 · The web has 5 arrows: grass to rabbit, rabbit to fox, grass to mouse, mouse to fox, and mouse to owl.
  9. Both tend to increase, since extra food at the bottom supports more life above · More grass feeds more grasshoppers, and more grasshoppers feed more frogs. The good news travels up the chain.
  10. Snakes decline from hunger, and hawks lean harder on frogs and sparrows · Losing mice starves the snakes, and hawks must then rely more on their other prey.
Worksheet · LightMySky