Biology New Procedure Item Template
Cellular Respiration in Peas
Directions: Use the following information to answer questions 1 through 9.
Miguel wanted to find out the difference in the rate of cellular respiration between dry and germinated
peas. He had heard the dry peas were alive and wanted to see if they would still carry out cellular
respiration. He decided to focus on one component of air: oxygen. He remembered that oxygen was
taken in along with glucose during cellular respiration. Remember germinated means that the plant has
been soaked in water and is beginning to sprout.
Question: What is the difference between the amount of oxygen taken in during cellular respiration
between dry and germinated peas?
Hypothesis: Germinating pea seeds will take up more oxygen than the dry pea seeds because they are
growing and need more energy, which is made through cellular respiration.
Materials:
Respirometers: Glass vials closed with a stopper that has a pipette inserted through the stopper (see
diagram)
Germinating pea seeds
Dry pea seeds
Glass beads
Absorbent cotton soaked in KOH
!
Dry cotton to protect the seeds
Water bath
Timer
Investigation Setup Diagram:
The respirometers are
submerged in the
water in this beaker to
close the system. As
the respiring peas use
up the oxygen in the
respirometer, the
water enters the
pipettes as indicated
by the arrows.
Water enters pipette
Vial on Left
Germinating
peas in a
closed vial.
The KOH will
remove the
CO2, so the
only gas in the
vial is O2
Vial on Right
Dry peas in a
closed vial.
The KOH will
remove the
CO2, so the
only gas in the
vial is O2
Biology New Procedure Item Template
Procedure:
1. Set up the respirometers—as shown in the Investigation Setup diagram by following instructions in
#2-8
2. Place one absorbent cotton ball in the bottom of the vial and drop exactly 5 ml of KOH on to the
cotton.
3. Place one non-absorbent cotton ball over the KOH cotton ball. The KOH will react with the CO2 and
eliminate the CO2 from the vial so you will only focus on Oxygen gas.
4. Place equal volumes of each of the germinated seeds, the dry seeds and the glass beads into each
respirometer.
5. Be sure to tightly seal each vial with the cork. The cork as been prepared by inserting a pipette into
the hole and sealed tightly.
6. Submerge the vials into a basin of room temperature water so that the water just barely enters the top
of the pipette.
7. Record the initial reading where the water level is inside the pipette.
8. Set your timer and take the reading where the water level is inside the pipette at 5 minutes, 10
minutes, 15 minutes and 20 minutes.
9. Repeat Steps 2-8 at least two more times.
Data: The table below shows the change in water level inside the pipette at each time interval for the
germinated peas, the dry peas and the beads.
Measurement of Oxygen Consumption by germinated peas and dry peas at room temperature
Time
(min)
Amount of water that entered the
pipette for each vial (ml)
Germinated Peas
Dry Peas
5
10
15
20
Graph: The data above was plotted below:
.07
.14
.20
.27
.03
.05
.05
.07
Biology New Procedure Item Template
INQ-F(1)
In the table below list 3 controls in this investigation
2 Why are the vials placed under water creating a closed system?
o
o
o
o
A. To control the evaporation of water
B. To capture the oxygen produced by the peas
C. To see if limiting the amount of air affects the rate of cellular respiration
D. To prevent atmospheric CO2 from replacing the CO2 removed by KOH
3 Which variable was the manipulated (changed) variable in this investigation?
o
o
o
o
SYS-B(2)
INQ-B(1)
A. The presence or absence of oxygen
B. The type of “seed” placed in the vial.
C. The presence or absence of carbon dioxide
D. Whether the plant system was open or closed to the atmosphere
4 Which variable was the responding (dependent) variable in this investigation?
Write your answer in this box:
INQ-B(1)
Biology New Procedure Item Template
5 Write a conclusion for this investigation.
In your conclusion, be sure to:
 Answer the investigative question.
 What were the Big Ideas (important concepts) from this investigation?
o Include supporting data from the Measurement of Oxygen Consumption by
germinated peas, dry peas and beads at room temperature table and graph to support
each of your big ideas.
o Explain how these data support your conclusion.
 Provide a scientific explanation for the pattern in the data.
Question:
What is the difference between the amount of oxygen taken in during cellular respiration between dry and
germinated plants?
Conclusion:
INQ-C(1)
Biology New Procedure Item Template
6 List the inputs of matter and energy for Cellular Respiration. Use words or chemical symbols.
LS1-A(1)
Write your answer in this box:
7 List the outputs of matter and energy for Cellular Respiration. Use words or chemical symbols.
Write your answer in this box:
8. Miguel’s lab partner, Shawnie asked what might happen if a live cricket were place in
the vial instead of peas. Design an experiment to test Shawie’s question.
a. Plan a controlled experiment to answer the Shawnies’ question. You may use any
materials and equipment in your procedure.
Be sure your procedure includes:





logical steps to do the experiment
two controlled (kept the same)
variables
one manipulated (independent)
variable
one responding (dependent)
variable
how often measurements should
be taken and recorded
LS1-A(1)
Cellular Respiration in Peas – Biology EOC Scenario, Seattle PS
Question: What is the effect of placing a live cricket into the vial on the amount
of oxygen consumed in the vial?
Procedure:
Seattle Public Schools October 2012
Cellular Respiration in Peas – Biology EOC Scenario, Seattle PS
Seattle Public Schools October 2012