Some seeds have to wait for years before they are able to germinate. During this time, seeds cannot make their own food because they lack leaves. Therefore, in order for a seed to stay alive or to grow it needs to use stored energy reserves and undergo cellular respiration. To fulfill the high-energy needs of a germinating seedling, cellular respiration increases as a seed emerges from dormancy and begins germinating. However, seeds respire at a lower rate throughout dormancy.
When plants use sugars stored in their leaves or seeds they undergo cellular respiration
Sugar + Oxygen → Carbon dioxide + Water + Energy (ATP)
Bromothymol blue is a chemical for weak and . The chemical is also used for observing activities or respiratory indicators (turns green then yellow as CO2 is added). In this experiment we will be using Bromothymol blue to determine if CO2 is present or not.
Hypothesis: The germinating pea seed will undergo respiration where as the dormant pea seeds will not.
Independent Variable: Pea Seeds
Dependent Variables: CO2 released
Control: No seeds
Materials: 3x small test tubes, 3x 125ml Erlenmeyer flask, Dormant Pea Seeds, Germinating Pea seeds, Parafilm, Bromothymol Blue, Small beaker.
Procedures:
- Obtain 3x Erlenmeyer flask, 3x test tube, 15 ml of bromothymol Blue indicator, 25x germinating pea seeds, 25x dormant pea seeds and a small beaker.
- Slightly wet a paper towel and put in at the bottom of flask number 1.
- Put 25 germinating pea seeds into flask 1.
- Put 1x test tube into flask one with 5 ml of bromothymol blue in the test tube.
- Put 25 Dormant pea seeds into flask number 2.
- Put 1x test tube into flask 2 with 5 ml of bromothymol blue in the test tube.
- Put 1x test tube into flask 3 with 5 ml of bromothymol blue in the test tube.
- Cover all flasks with parafilm tightly.
- Wait over 72 hours.
- Observe and find evidence of respiration.
- Record data.
The end color of BTB with different seeds
Evauluations:
The rate of respiration could not be determine, however we do know that respiration was occurring in the geminating seeds.
Limitations:
Abiotic factors were not considered on the rate of respiration. We could not measure the amount of CO2 release by the germinating seeds thus we could not create a general knowledge of the rate of respiration by the germinating seeds.
Conclusion:
The germinating seeds were the only seeds that showed sign of respiration. This was determined by the yellow color of the BTB solution which indicates CO2 gas present. Dormant seeds had no evidence of respiration because the BTB solution remained the same color. The flask with no seeds had no respiration because there was no organism present to under cellular respiration.
