Week 3 Assignment 2 Experiment & Data Collection

In Weeks 2-3, you will set up your experiment and complete the data collection assignment.

1. Materials

• Beakers or measuring cups (with mL)
• Small, clear, plastic cups (around 200 mL)
• Live Duckweed (at least 100 fronds). Ideally, try to find Lemna minor. However, any Lemna species will work- just make sure to use only one species in your study. You can use one of these options:
• (at least 100 fronds)
• Check a local petstore
• Tweezers (or un-folded paper clip)
• 2L distilled water
• (or comparable fertilizer)
• Permanent marker
• Masking tape
• Stirring rod or spoon

1. Instructions
2. Label Cups
3. Gather your materials from the list.
4. Set out 4 large beakers and label them with masking tape and the permanent marker as Solution A, Solution B, and Solution C.
5. Set out 8 small, clear cups and label them with the permanent marker numbers 1-8 (i.e. the first cup should be labeled #1, the second cup should be labeled #2, etc.).
6. Create Solutions
7. Obtain 2L of distilled water.
8. Obtain a bottle of Miracle-Gro Liquid Houseplant food.
9. Solution A
10. Using a small beaker, measure out 60 mL of Miracle-Gro Liquid Houseplant food. Pour into the large beaker labeled Solution A.
11. Fill the beaker with non-chlorinated water until the solution reaches the 300 mL mark.
12. Stir the solution until fully mixed.
13. Solution B
14. Using a small beaker, measure out 15 mL of Miracle-Gro Liquid Houseplant food. Pour into the large beaker labeled Solution B.
15. Fill the beaker with non-chlorinated water until the solution reaches the 300 mL mark.
16. Stir the solution until fully mixed.
17. Solution C
18. Add 4 drops of Miracle-Gro Liquid Houseplant food into the large beaker labeled Solution C.
19. Fill the beaker with non-chlorinated water until the solution reaches the 300 mL mark.
20. Stir the solution until fully mixed.
21. Set up Experiment
22. Find an appropriate location to set your experiment up.
23. This location should be a relatively undisturbed area (i.e. not where your cat will knock your cups over) with stable room temperature.
24. Ideally, this location should be near a window with light. If you do not have an area with natural sunlight, you can place a desk lamp over your cups (trying to make sure that each cup has equal light).
25. Set your labeled cups out in your location.
26. Carefully pour 150 mL of pure un-chlorinated water into Cup #1.
27. Using tweezers or an unfolded paper clip, carefully transfer an individual duckweed frond into Cup #1, gently laying it on the surface of the water. Add 9 more to have a total of 10 duckweed fronds in the cup.
28. Repeat with the remaining cups using the following treatments in the table below in each respectively labeled cup.
29. Carefully clean your workspace and any used beakers.
30. Take a picture of your full experimental setup.
31. Cup #
32. Treatment
33. 1
34. 10 duckweed fronds, 150 mL of pure water
35. 2
36. 10 duckweed fronds, 150 mL of pure water
37. 3
38. 10 duckweed fronds, 150 mL of Solution A
39. 4
40. 10 duckweed fronds, 150 mL of Solution A
41. 5
42. 10 duckweed fronds, 150 mL of Solution B
43. 6
44. 10 duckweed fronds, 150 mL of Solution B
45. 7
46. 10 duckweed fronds, 150 mL of Solution C
47. 8
48. 10 duckweed fronds, 150 mL of Solution C
49. Data Collection (Weeks 2-3)
50. You will be collecting data every day for 10 days on each cup, completing counts on how many duckweed fronds you see.
51. As you examine each cup, you may need to use your tweezers to gently separate the fronds.
52. As you count, record your data in these
53. . Be sure to be signed into Google, otherwise, you won’t be able to access.
54. Your total count for each cup will be entered into the corresponding table in the column labeled Daily Frond Count.
55. Calculate the difference between the daily frond count and the previous count and record this in the column labeled New Frond Growth.
56. Divide the New Frond Growth by the previous count and record this in the Rate of Change column.
57. On Day 10, take a final picture of the experiment. Submit a copy or screenshot of your completed template.