The document describes an experiment on transpiration rate in plants. Two plants were placed in separate beakers, one in bright light and one in the dark. A data logger measured the humidity every 30 minutes over 2 hours. The results show that the plant in bright light had a lower humidity level, indicating a higher transpiration rate, while the plant in dark conditions had steady humidity, showing a lower transpiration rate. Light stimulates transpiration by opening stomata and warming the leaf.

1. Short Breath Cold
Sweat

2. •Transpiration is a process in which the water
loss through the plant via its stomata and
lenticels into its external environment.
•Among the factors that affects transpiration
process are light, temperature, humidity, wind
and soil water.
•Plants transpire more rapidly in the light than
in the dark. This is largely because light
stimulates the opening of the stomata .Light
also speeds up transpiration by warming the
leaf.

3. ENGAGE
The plants are sealed in a beaker and left under the
hot sun. After several hours, what can you observed
at the inner surface of the beaker? And HOW those
it happened?
AfterBefore

4. Data logger
Data logger
Humidity
sensor
Humidity
sensor
EMPOWER

5. EMPOWER
Time(mm:ss)
Humidity of plant in bright place
I/O-1(%)
Humidity of plant in dark place I/O-
2(%)
3:35 27.302 28.095
4:35 27.143 28.095
5:35 27.302 28.254
6:35 27.143 28.254
7:35 27.302 28.254
8:35 27.302 28.413
9:35 27.302 28.571
10:35 27.143 28.413
11:35 27.302 28.413
12:35 27.302 28.571
13:35 27.302 28.571

6. Time(mm:ss)
Humidity of plant in bright place
I/O-1(%)
Humidity of plant in dark place
I/O-2(%)
14:35 27.302 28.413
15:35 27.302 28.571
16:35 27.143 28.413
17:35 26.984 28.571
18:35 27.143 28.73
19:35 26.984 28.73
20:35 26.825 28.73
21:35 27.46 28.73
22:35 26.349 28.73
23:35 26.032 28.73
24:35:00 26.825 28.571
25:35:00 26.667 28.73
26:35:00 26.349 28.73
27:35:00 26.349 28.73
28:35:00 26.825 28.571
29:35:00 26.825 28.73
30:35:00 26.19 28.73

7. Time(mm:ss)
Humidity of plant in bright place
I/O-1(%)
Humidity of plant in dark place
I/O-2(%)
31:35:00 26.984 28.73
32:35:00 27.302 28.73
33:35:00 25.873 28.73
34:35:00 25.714 28.73
35:35:00 24.921 28.73
36:35:00 26.032 28.73
37:35:00 26.19 28.73
38:35:00 25.873 28.73
39:35:00 26.349 28.73
40:35:00 25.238 28.889
41:35:00 25.556 28.73
42:35:00 25.714 28.73
43:35:00 26.508 28.889
44:35:00 27.302 28.73
45:35:00 26.984 28.73
46:35:00 26.349 28.73
47:35:00 26.825 28.73
48:35:00 26.032 28.889

8. Time(mm:ss)
Humidity of plant in bright place
I/O-1(%)
Humidity of plant in dark place I/O-
2(%)
49:35:00 25.873 28.73
50:35:00 24.921 28.889
51:35:00 25.714 28.889
52:35:00 26.508 28.889
53:35:00 25.397 28.889
54:35:00 26.984 28.889
55:35:00 25.714 28.889
56:35:00 24.762 28.889
57:35:00 25.397 28.889
58:35:00 25.397 28.889
59:35:00 25.873 29.048
0:35 26.19 29.048

9. Humidity
of plant in
bright place
Humidity
of plant
in bright
place

10. EMPOWER
Discussions
1. What can you observed from the both beakers after
1 hours?
2.From the graph, which condition shows the lowest
rate of transpiration ?
3.From the graph, which condition shows the highest
rate of transpiration ?
4.How the presence of light affect transpiration
process?
5.What are relationship between transpiration rate
and humidity? Explain how it happened

11. Answer
1. Beaker that places at bright place have water droplets
on the surface of the beaker compare to surface of
the beaker at dark place.
2.Plant in the beaker at dark place show the lowest
rate of transpiration.
3. Plant in the beaker at bright place show the highest
rate of transpiration.
4.When the light present, the transpiration rate
increase.
5.If the transpiration rate increase, humidity also
increase. This is due to the water loss in plant. Water
changed into water vapor and this condition will
increase the humidity of surrounding air.

12. ENHANCE
• The man was having a heavy sweating after he do a
run during the hot day.
Is there any similarities between transpiration and
sweating process? If yes, what is the comparison
between both of the process?

13. UNIQUE FEATURES
By using data logger, students can get more accurate
results and this can prevent parallax error during
taking the reading.
Time for the students to carry out this experiment
can be save because same sensors can be run at the
same time.
From the graph, the students can see the changes
occur during the experiments was conducted.
Students can learn how to handle the data logger and
also explore new technology that can be used during
learning and teaching process.