How living things move carbon

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. 1.

   Ari reads a carbon cycle diagram of a meadow. The arrow from the air to the grass has a blank label. Which process belongs on it?

   • Cellular respiration, which takes carbon dioxide in
   • No process, since the grass makes its own carbon
   • Decomposition, which takes carbon dioxide in
   • Photosynthesis, which takes carbon dioxide in
2. 2.

   Bo reads the arrow from the grass back to the air. It carries carbon dioxide, but its label is blank. Which process belongs on it?

   • Decomposition, which gives carbon dioxide back
   • No process, since plants do not release carbon dioxide
   • Cellular respiration, which gives carbon dioxide back
   • Photosynthesis, which gives carbon dioxide back
3. 3.

   Esme reads the arrow from the decomposers to the air. It carries carbon dioxide, and its label is blank. Which process belongs on it?

   • Dissolving, which moves carbon dioxide into the ocean
   • Destruction, which makes the carbon in remains vanish
   • Decomposition, which returns carbon dioxide to the air
   • Photosynthesis, which returns carbon dioxide to the air
4. 4.

   Kira reads the arrows between the air and box X. Carbon dioxide gas dissolves into box X and leaves it again. Which store is box X?

   • The ocean
   • A rock layer
   • The soil
   • No store, since carbon dioxide cannot move into water
5. 5.

   Flow diagram of the carbon cycle (model, not to scale), Earth as a whole. Luz reads a carbon store diagram. Box W holds most of Earth’s carbon. Which store is box W?

   • Rock layers
   • The atmosphere
   • The soil
   • Plants and algae
6. 6.

   Milo reads a glossary entry. Which meaning fits the term carbon reservoir?

   • A process that takes carbon dioxide from the air into a leaf
   • An organism, such as a fungus, that breaks down old remains
   • A store that holds carbon for a time, such as the air or the ocean
   • A kind of rock that has no way to give its carbon back
7. 7.

   Noah reads a glossary entry. Which meaning fits the term decomposer?

   • An organism, such as a fungus, that breaks down remains and wastes
   • An organism, such as grass, that makes sugar from carbon dioxide and light
   • An organism, such as a fungus, that destroys the carbon in remains
   • An organism, such as a grasshopper, that gets carbon from plant material
8. 8.

   Ren sees that grass takes in carbon dioxide in light. At night the grass cells still use sugar for energy. Which gas do they give off?

   • No gas, since plants do not release carbon dioxide
   • Carbon dioxide, from cellular respiration
   • Carbon, as new atoms made from the sugar
   • Oxygen, from photosynthesis at night
9. 9.

   Tala follows carbon in a fallen leaf. Decomposers break the leaf down. In what form does much of its carbon return to the air?

   • As nothing, since decomposers destroy the carbon
   • As carbon dioxide gas
   • As oxygen gas, made from the leaf
   • As sugar, made new by the decomposers
10. 10.

    Zee reads two arrows between the air and the ocean surface. What do they show?

    • The ocean takes no part, since the arrows show wind
    • Carbon dioxide moves into the water and is destroyed there
    • Carbon dioxide moves in one direction, from the water to the air
    • Carbon dioxide moves into the water and out of it again