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?

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

   • Dissolving, which moves carbon dioxide into the ocean
   • Decomposition, which returns carbon dioxide to the air
   • Photosynthesis, which returns carbon dioxide to the air
   • Destruction, which makes the carbon in remains vanish
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 atmosphere
   • A rock layer
   • The soil
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?

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

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

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

   • A kind of rock that has no way to give its carbon back
   • 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
7. 7.

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

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

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

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