How living things move carbon

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. 1.

   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?

   • Cellular respiration, which gives carbon dioxide back
   • Decomposition, which gives carbon dioxide back
   • No process, since plants do not release carbon dioxide
   • Photosynthesis, which gives carbon dioxide back
2. 2.

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

   • Decomposition, which returns carbon dioxide to the air
   • Destruction, which makes the carbon in remains vanish
   • Photosynthesis, which returns carbon dioxide to the air
   • Dissolving, which moves carbon dioxide into the ocean
3. 3.

   Jun reads a meadow diagram. Box W supplies the carbon dioxide that the grass takes in and receives what the grass gives back. Which store is box W?

   • The ocean
   • The soil
   • A rock layer
   • The atmosphere
4. 4.

   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?

   • Plants and algae
   • The soil
   • The atmosphere
   • Rock layers
5. 5.

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

   • A process that takes carbon dioxide from the air into a leaf
   • A kind of rock that has no way to give its carbon back
   • A store that holds carbon for a time, such as the air or the ocean
   • An organism, such as a fungus, that breaks down old remains
6. 6.

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

   • An organism, such as a fungus, that destroys the carbon in remains
   • An organism, such as a grasshopper, that gets carbon from plant material
   • An organism, such as grass, that makes sugar from carbon dioxide and light
   • An organism, such as a fungus, that breaks down remains and wastes
7. 7.

   Pia reads a glossary entry. Which meaning fits the term carbon cycle?

   • The flow of energy from the Sun through food to heat
   • The path of carbon until decomposers destroy it for good
   • The movement of carbon among air, water, rock and living things
   • The making of new carbon atoms by green plants and algae
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?

   • Carbon dioxide, from cellular respiration
   • Carbon, as new atoms made from the sugar
   • No gas, since plants do not release carbon dioxide
   • 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 oxygen gas, made from the leaf
   • As carbon dioxide gas
   • 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 out of it again
    • Carbon dioxide moves in one direction, from the water to the air
    • Carbon dioxide moves into the water and is destroyed there