How does germination affect the respiration that cells undergo? The main purpose of this lab was to test whether there is a difference in germinating cells or non-germinating cells.
My hypothesis for this experiment was that if there are more germinating cells, then they will respire more than the dry cells over time. This is because germinating cells are more likely to respire more and give off more carbon dioxide than non-germinating cells.
The materials needed for this lab are:
two large trays, thermometers, water, ice, six vials, steel washers, 100 mL graduated cylinder, glass beads, germinating peas, dry non-germinating peas, cotton ball, non-absorbent rayon, 15% potassium hydroxide (KOH), graduated pipet, and a stopper.
Be sure to use gloves, goggles, and an apron for this lab because the KOH is corrosive. BE VERY CAREFUL.
The procedure for this lab is as follows:
1. Set up the waterbaths in the large trays. One should be less than 10 degrees Celsius at all times by using ice.
2. Obtain six vials and place steel washers at the bottoms. Number these vials.
3. Fill the graduated cylinder halfway with water. Add 10 germinating peas and take a reading of the displaced water. Calculate the difference and record this data as the volume of the germinating peas.
4. Redo step 3 but by adding 10 dry non-germinating peas and glass beads until the water level is the same as the germinating peas.
5. Redo step 3 but by adding glass beads to the water level of the germinating peas. This is what is being compared and tested against.
6. Dry the peas and beads and repeat steps 3-5 for the second set of vials.
7. Place the cotton balls in each of the bottoms of the vials.
8. Using a pipet, add 1 mL of the 15% KOH to the cotton ball. Then, add a piece of rayon on top of the cotton ball.
9. Place the germinating peas, non-germinating peas and glass beads, and glass beads in vials 1-3 and 4-6.
10. Insert the graduated pipet into the wide end of the stopper. Be sure the tapered end of the pipet is furthest away from the stopper. Do this for all of the vials.
11. Insert the stopper into the vials. Place a washer over the pipet and let it rest on the stopper.
12. Place the first 3 vials in the room-temperature waterbath and the last 3 in the chilled waterbath with thermometers in both. Be sure that the tips of the pipets are resting on the edge and not in the water.
13. Add a drop of food coloring to the tip of the pipet and wait one minute. Carefully immerse the vials into the water. Let the vials sit and equilibriate for 5 minutes before recording.
14. Record the initial reading and temperature in your data table and every 5 minutes for 30 minutes record the new readings.
15. When all of the readings have been taken, calculate the difference and corrected difference for each result.
Difference= (initial-final)
Corrected Difference= (initial pea reading-pea reading at time)-(initial bead reading- bead reading at time)
16. Graph results
(Time is the independent variable and the amount of difference is the dependent variable.)
Temp. | Time | Reading for Germinating peas | Difference | Corr. Diff. | Reading for Dry peas | Difference | Corr. Diff. | Reading Beads | Difference |
25 | 0 | .91 | 0 | 0 | .92 | 0 | 0 | .93 | 0 |
25 | 5 | .84 | .07 | .05 | .89 | .03 | .01 | .91 | .02 |
25 | 10 | .77 | .14 | .11 | .87 | .05 | .02 | .90 | .03 |
25 | 15 | .71 | .20 | .17 | .86 | .06 | .03 | .90 | .03 |
25 | 20 | .64 | .27 | .24 | .85 | .07 | .04 | .90 | .03 |
25 | 25 | .58 | .33 | .30 | .84 | .08 | .05 | .90 | .03 |
25 | 30 | .51 | .40 | .37 | .83 | .09 | .06 | .90 | .03 |
Temp. | Time | Reading for Germinating peas | Difference | Corr. Diff. | Reading for Dry peas | Difference | Corr. Diff. | Reading Beads | Difference |
8 | 0 | .92 | 0 | 0 | .91 | 0 | 0 | .95 | 0 |
8 | 5 | .88 | .04 | .03 | .90 | .01 | .00 | .94 | .01 |
8 | 10 | .85 | .07 | .05 | .87 | .04 | .02 | .93 | .02 |
8 | 15 | .83 | .09 | .06 | .86 | .05 | .02 | .92 | .03 |
8 | 20 | .80 | .12 | .09 | .85 | .06 | .03 | .92 | .03 |
8 | 25 | .77 | .15 | .12 | .84 | .07 | .04 | .92 | .03 |
8 | 30 | .74 | .18 | .14 | .82 | .09 | .05 | .91 | .04 |
These are my results of the experiment.
My results show that in the colder water, the peas had a much lower difference than in the room temperature water. It also showed that as time went on the difference grew, although not as consistent as expected. Lastly, it showed that the germinating peas had a higher difference than the dry peas, as my hypothesis predicted.
