Seed Germination Lab Alex, Cortney, Kirsten, and Thalia
Question: Will the intensity of light change with different color tissue paper, thus affecting the seeds germination?
Hypotheses: If the germination rate of the seeds is affected, then the seeds placed under the white tissue paper will germinate the fastest.
Materials Image A. Plant stand Tape Plant light intensity Scissors meter 1 sheet of tissue paper of the (Image A. ) Water Eye Dropper 70 Pea seeds 7 Petri dishes following colors a. green b. red c. white d. black Paper e. yellow Writing utensil f. blue g. pink
Procedure: 1. Obtain 21 petri dishes and place 4 layers of damp paper towel (fit to the dish) on the bottom of the dish. 2. Place 10 pea seeds in each dish on top of the damp paper towel. 3. Label petri dishes as follows: (3 dishes) 1 A, 1 B, 1 C [GREEN] “ 5 A, 5 B, 5 C [YELLOW] " 2 A, 2 B, 2 C [RED] " 6 A, 6 B, 6 C [BLUE] " 3 A, 3 B, 3 C [WHITE] “ 7 A, 7 B, 7 C [PINK] " 4 A, 4 B, 4 C [BLACK] " 8 A, 8 B, 8 C [CONTROL]
Labeled petri dishes (to the left) Paper towel cutouts (to the right)
(cont. ) 4. To measure the intensity of light through tissue paper, hold tissue paper under light. Then hold light intensity meter under tissue paper to obtain proper measurements. Record readings. [we also included a diagram] 5. Repeat step 4 for each color tissue paper. 6. Place tissue paper atop petri dishes, both under the light on the plant stand. 7. Place petri dishes in order (above, slide 6).
(cont. ) 8. Use graduated pipette to add 40 drops of water to petri dish every day to keep towel moist. 9. Turn plant stand light on and leave on continuously throughout the experiment. 10. Observe any changes each day and check for signs of germination. GERMINATION: WHEN THE HYPOCOTYL IS SHOWING. 11. Repeat step 9 for a maximum of 1 week, record daily observations in data table.
Shown: Each of the variables in the plant stand with their respected tissue paper atop. The petri dishes without tissue paper are the control groups.
After completed procedure, this is what the layout of our experiment looked like.
Data Table-Average Percent Germination Day 1 Day 2 Day 3 Day 4 1 -Green 0% 17% 67% 90% 2 -Red 0% 0% 93% 3 -White 0% 7% 83% 4 -Black 0% 47% 83% 5 -Yellow 0% 63% 67% 73% 6 -Blue 0% 30% 70% 80% 7 -Pink 0% 0% 47% 63% 8 -Control 0% 10% 77% 80%
Percent seeds germinated (%) Results
Variables The distance from the light to the seeds were not the same. ○ With a bit of readjusting, the shelves are now 16 cm. Amount of water: In the beginning, the seeds were not given enough water ○ After a good dousing of water, they finally started to germinate.
Other Questions What would have happened if we used a different type of seed? Would the results have been different if we used two sheets of tissue paper for each variable? Would the results vary in a colder/warmer temperature?
Conclusion/Analysis: In conclusion, the pea seeds most affected by light intensity were the seeds under the red tissue paper. Results from the experiment were very unexpected as the percentage of seeds germinated were high in each category. This leads us to believe that in our experiment, the color of the tissue paper only slightly affected the speed of germination. We have also concluded that the tissue paper may have been better substituted with an actual light bulb of the desired color. For example, a red light bulb giving off red light may have changed the outcome of the percentage of seeds that germinated.