Effects of Germination
Time Length on Pea
Respiration
Problem: What effect does germination time have on
pea respiration?
Background
With glucose and oxygen, plants are able to
perform cellular respiration, creating CO2;
this process extracts free energy from carbon
compounds for ATP production. Different
factors, like germination period, impact the
rate of cellular respiration.
Hypothesis
As the length of germination of the pea
plants increases, the rate of cellular
respiration will increase because more
oxygen will be needed as the plant grows.
Procedures
1. Soak different sets of peas for 24, 48, and 72 hour
periods.
2. Put 25 peas for each time in their respective test tube.
Add glass beads to compensate for difference in volume,
maintaining a volume of 10 mL determined through
water displacement.
3. Record pressure changes for 900 seconds.
Data
Table:
Length of
Room Temperature: 18 degrees Celsius.
Germination
Volume of Peas in
Test Tube
Volume of Glass
Beads
Rate of Change in
Pressure (kPa/sec)
24 hours
8 mL
2 mL
-7.753e-5
48 hours
8 mL
2 mL
-0.001253
72 hours
10 mL
0 mL
-0.001989
Control
10 mL
0 mL
-0.0006832
Results
Pressure 1: 72 hour
period
Pressure 2: 48
hour period
Pressure 3: 24
Hour Period
Results Cont.
Pressure 1: 48 hour
period
Pressure 2: Control
(Only Beads)
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Discussion
Different weather conditions give different amounts
of moisture availability
Peas have higher cellular respiration rates with
more germination time
Useful in agriculture to determine optimal
germination period, optimise plant growth
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Conclusion
72 hours best time for cellular respiration based on 3
tested time periods
Expect plateau in increase of cellular respiration rate
sometime beyond germination time of 72 hours
Other conditions to consider to maximize growth:
o Temperature
o Air Pressure
o Moisture Amount
Experimental Errors
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Did not run control while testing peas
Experienced changes in pressure for the
control
Did not keep the amount of water that the
peas were submerged in constant during
respective soaking periods