# IA Activity

Topics: Water, Humidity, Transpiration Pages: 6 (798 words) Published: February 3, 2014
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Title: Rate of transpiration
I found interesting to know how different environmental factors affect the rate of transpiration. There are different environmental factors, such as light intensity, humidity, wind and temperature that affect the rate of transpiration. Transpiration is a topic 9 in our Biology higher level book. I have read all the information through this chapter and researched some extra information. Based on this information that I had known I decided to take experiment of environmental factor of wind temperature. I am aware of different factors that can affect the rate of transpiration in plants: light, humidity, wind, temperature, soil water and carbon dioxide. My independent variable is levels of temperature of wind.

Aim: To know how temperature of wind as an environmental factor affects the transpiration rate of celery. Research question: How do different levels of wind temperature affect the rate of transpiration in celeries? Four environmental conditions will be used to measure the rate of transpiration in celeries. Background: Transpiration is a process of water vapour loss into the atmosphere from the leaves of the plants. Water vapour exits through the plant stomata, which opens to intake carbon dioxide and let out oxygen. Wind carries away humid air around the plant, therefore the rate of transpiration in plants shall increase.

Hypothesis: If the celery is surrounded by humid air, then the rate of transpiration reduces. High concentration of water surrounds the leaf, which has lower water concentration inside. When wind occurs it carries away the humid air. But if the temperature of wind is high then the plant would not absorb water well. Therefore, a lower temperature of wind causes greater rate of transpiration. Variables:

a) Independent: temperature of wind
b) Dependent: rate of transpiration
c) Controlled: Volume of water(ml)
Celery size(cm)
Time(min)
Speed of the hairdryer
Control of variables:
2.5 ml
Celery size
20 cm
Time
3 min
Speed
1 speed of the hairdryer

Materials for the lab: celery stalks, red food coloring, potometer, hairdryer, digital balance, knife, cutting board, distilled water, stopwatch, spoon, and thermometer.

Procedure:
Step one: take a beaker with distilled water and add red food coloring. Mix thoroughly using a spoon. Step two: take a syringe and fill it to 2.5 ml with this colored water. Prepare potometer and put the syringe into it. Step three: put celery into the potometer. Turn the knob on the potometer to the left, and then slowly add the liquid to fill up the tube of the potometer (10 cm). (Refer to the diagram)

Step four: (Neutral temperature 20 C°)
Start the stopwatch, turn the knob to the right and wait for 3 minutes. Note: for each trial temperature increases by five degree. I used different hairdryer temperatures to measure how they affect the rate of transpiration. First temperature is 40C°. Second temperature is 45C°. Third temperature is 50C°. The temperatures were written on the hairdryer. Step five: record the results.

Raw data:
Temperature(C°)
Initial volume of water (cm3)
Final volume of water(cm3)
20
10
6.4
7.2
7.0
7.4
40
10
7.2
6.8
6.5
6.7
45
10
6.1
6.4
6.3
6.5
50
10
5.8
5.9
5.7
6.1

Data table:
Temperature (C°)
Volume of water absorbed (cm3)
Percentage of water absorbed (%)
Average volume of water absorbed (cm3)
Average percentage of water absorbed (%)
20
3.6
2.8
3.0
2.6
36
28
30
26
3
30
40
2.8
3.2
3.5
3.3
28
32
35
33
3,2
32
45
3.9
3.6
3.7
3.5
39
36
37
35
3,7
36.8
50
4.2
4.1
4.3
3.9
42
41
43
39
4,1
42.3

Graph:

Data processing:
According to my research, the lower the temperature the higher the rate of transpiration. My results showed the opposite of what generally should happen. The standard...

Bibliography: Whiting, David, Michael Roll, and Larry Vickerman. "Plant Growth Factors: Photosynthesis, Respiration, and Transpiration." Colorado State University Extension. N.p., n.d. Web. 6 Jan 2014. .
"Transpiration - Water Movement through Plants." Plant & Soil Sciences eLibraryPRO. N.p.. Web. 6 Jan 2014. .
József, Zsembeli, and Juhász Csaba. "Tankonyvtar." Water management. N.p., n.d. Web. 6 Jan 2014. .