6. Why is it necessary to correct the readings from the peas with the readings from the beads?
To show the actual rate at which cellular respiration occurs in the peas. The beads were the control variable.
7. Explain the effect of germination (versus non-germination) on peas seed respiration .
Germination, the seeds are growing and need to respirate to grow.
the results shown in the sample graph in your lab manual. As the temperature increased, enzymes denatured so germination was inhibited.
9. What is the purpose of KOH in this experiment?
KOH pellets absorb carbon dioxide and form an insoluble precipitate
10. Why did the vial have to be completely sealed around the stopper?
The stopper at the top of the vial had to be completely sealed so that no gas could leak out of the vial and so that no water would be able to enter into the vial.
11. If you used the same experimental design to compare the rates of respiration of a 25 g reptile and a 25 g mammal, at 100 degrees Celsius, what results would you expect? Explain your reasoning.
I would expect the respiration to be higher in the mammal since they are warm blooded.
12. If respiration in a small mammal were studied at both room temperature 21 degrees Celsius and 10 degrees Celsius, what results would you predict? Explain your reasoning.
Respiration would be higher at 21 degrees because the animal would have to keep his body temperature up.
13. Explain why water moved into the respirometer pipettes .
While the peas underwent cellular respiration, they consumed oxygen and released carbon dioxide. The carbon dioxide reacted with the KOH resulting in a decrease in the volume of gas in the pipette and the vial. Because the pipette tip was exposed to the water bath, water moved into the pipette.
13. Design an experiment to examine the rates of cellular respiration in peas that have been germinating for 0, 24, 48 and 72 hours. What results would you expect? Why?
Set up four respirometers which have one of the following-Seeds that have not begun to germinate; Seeds that have been germinating for one day; Seeds that have been germinating for two days; Seeds that have been germinating for three days. It is expected that there will be no oxygen used by the seeds that have not germinated yet. The seeds that had been germinating for three days would consume the most oxygen.