Light reactions and the Calvin cycle

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. Read this first

   Use this

   Chloroplast cutaway (model, not to scale).

2. 1.

   Ari studies a chloroplast drawing. Part A is a stack of flat, disc-shaped thylakoids. What is A called?

   • The thylakoid lumen
   • The granum
   • The stroma
   • The outer membrane
3. 2.

   Bo studies a chloroplast drawing. Part D is the liquid-filled space around the stacks of thylakoids. What is D?

   • The thylakoid membrane
   • The stoma
   • The granum
   • The stroma
4. 3.

   Esme wants to find the chlorophyll that absorbs light in a chloroplast. Which part holds it?

   • The outer membrane
   • The fluid inside each thylakoid
   • The stroma
   • The thylakoid membranes
5. 4.

   “model, not to scale” Jun reads that chlorophyll absorbs light and its energy is stored in ATP and NADPH. Which stage is this?

   • Fermentation
   • The Calvin cycle
   • The light reactions
   • Glycolysis

6. Use this

   Flow diagram (model, not to scale), drawn inside a chloroplast. The name of the stage in box B is not shown.

7. 5.

   Kira reads that carbon dioxide is built into sugar (G3P) using ATP and NADPH. Which stage is this?

   • The light reactions
   • The Calvin cycle
   • The citric acid cycle
   • Cellular respiration
8. 6.

   Luz reads that water is split and oxygen is released. Which stage does this?

   • The Calvin cycle
   • Cellular respiration
   • The light reactions
   • Electron transport in a mitochondrion

9. Use this

   Flow diagram (model, not to scale), drawn inside a chloroplast. In the thylakoid membranes: water and a wavy arrow of light energy go in; oxygen comes out. In the stroma: carbon dioxide goes in; G3P comes out. Arrow B runs from the stroma back to the thylakoid membranes. What it carries is not shown.

10. 7.

    Noah reads a chloroplast diagram. Arrow B runs from the stroma back to the thylakoid membranes. What does B carry?

    • ATP and NADPH
    • Nothing, since ATP and NADPH are used up for good
    • G3P, made by the light reactions
    • ADP, Pi and NADP+
11. 8.

    Flow diagram (model, not to scale). Pia reads a chloroplast diagram. Arrow C leaves the thylakoid membranes and carries a gas out of the chloroplast. What does C carry, and where does it come from?

    • Oxygen, made from carbon dioxide
    • Hydrogen gas, made from split water
    • Carbon dioxide, left over from split water
    • Oxygen, made from split water
12. 9.

    The name of the sugar and the zone that builds it are not shown. Ren fills in box D, the sugar that leaves the chloroplast. What goes in D, and where is it built?

    • ATP, built in the stroma
    • G3P, built in the stroma
    • G3P, built in the thylakoid membranes
    • ATP, built in the thylakoid membranes

13. Use this

    Flow diagram (model, not to scale), drawn inside a chloroplast. In the stroma: NADPH goes in and is spent. Box E is an output box in the stroma. An arrow carries box E back to the thylakoid membranes. The name in box E is not shown.

14. 10.

    Zee fills in box E, made when the Calvin cycle spends NADPH. What goes in E?

    • Carbon dioxide
    • Nothing: the spent NADPH just disappears
    • NADPH
    • NADP+