4.7 (a) To investigate the influence of light intensity on the rate of photosynthesis.
-
Upload
dwain-wilkins -
Category
Documents
-
view
224 -
download
2
Transcript of 4.7 (a) To investigate the influence of light intensity on the rate of photosynthesis.
4.7 (a) To investigate the influence of light intensity on the rate of
photosynthesis
Step 1
Cut the stem of the elodea at an angle. Remove several leaves from the cut end of the stem.
Before you start get or make a copy of this
Table of results
Distance [d] from
light source(cm)
Light Intensity or 1/d
2
(No. of bubbles/ minute)
Average Trial 1 Trial 2 Trial 3
Step 2
Hook a paper clip onto the end of the elodea. Drop the elodea, stem up, into a boiling tube of pond water.
Step 3
Place the boiling tube, containing the elodea into a water bath at 25°C.
Step 4
Switch on the light source and place the water bath containing the elodea
15 cm from the lamp. Wait 5 minutes.
Step 5
Observe bubbles being released from the cut end of the stem. Count and record the number of bubbles released per minute. Repeat twice.
Step 6
Repeat the experiment, varying the distance between the water bath and the lamp.
Table of results:
Distance from light source
(cm)
Light Intensity or 1/d
2
(No. of bubbles/ minute)
Average Trial 1 Trial 2 Trial 3
Step 7
Plot a graph of light intensity against average no. of bubbles/minute.
Expected Graph
END