Plants use photosynthesis to convert carbon dioxide, water, and light energy into glucose and oxygen. Photosynthesis is carried out by the chloroplasts in plant leaves using the pigment chlorophyll. Experiments could test the importance of light by comparing plant growth with and without light, test the importance of carbon dioxide by using soda lime to absorb carbon dioxide from the air around plants, and test the importance of chlorophyll by observing the growth of variegated leaves that lack chloroplasts in yellow areas.

2. They can make their own food using small
inorganic molecules and light energy.
This process is called photosynthesis.
Word equation:
Carbon dioxide+water glucose+oxygen
Light
chlorophyll

8. How would you test for the
importance of light ?
How would you test for the
importance of CO2?
 how would you test for the
importance of chlorophyll?

9. Hint:
Soda lime
absorbs CO2
in air.

11. Hint:
Variegated
leaves have
yellow areas
with no
chloroplasts.

12. How could you test
the effect of:
Variable light
intensities?
Variable CO2
concentrations?
Variable
temperatures?

13. Nitrates: provide the plant with the
nitrogen needed to make amino acids
and thus proteins.
Magnesium: is needed to make
chlorophyll.
Predict how soil with no nitrates
/magnesium would affect plant
growth.

14. O2 level
falls