Lab: Interdependence of Organisms Interdependence Of Organisms

Question Being Answered:

How can the presence of one species benefit another in the same ecosystem?

Hypothesis:

If plants grow in soil that contains worms the plants growth will be greater because worms are able to help decompose organic matter and help distribute it through the soil in a form plants are able to use.

Process Of Lab:

In this lab you will grow two different groups of plants. Group A is considered the experimental group which will grow in soil with worms, Group B is considered the control group which will grow in soil without worms. After the plants grow you have to measure the plant growth for both groups and compare them.

Independent & Dependent

Independent Variable: Presence Of Worms

Dependent Variable: Plant Growth

Safety Procedure

Be sure to follow the safety procedure which means to

Wear safety goggles and lab gown while doing the experiment

Keep lab behavior purposeful

Look over the soil contents and make sure to follow warnings provided on any equipment

Wash hands and lab equipment once done with experiment

Treat living organisms with respect and provide proper care

Report any accidents that happen in the lab to your teacher

Lab Procedure

Step 1: Gather Materials

Two trays that are 10 cm 4’ deep

Potting soil

Lima bean seeds which need to be soaked overnight

Location with sunlight or growth lights

Worms

Graduated cylinder

Water

Black marker

Ruler with metric markings

Step 2: Prepare Two Trays Of Lima Bean Plants

Label the trays Control Group and Experimental Group

Add approximately 6-7 cm of soil to each tray

Plant 6 lima bean seeds in each tray being 2 cm deep and label the plants 1-6

Step 3: Give The Plants Water And Light During Sprouting Time

Keep the environments for both groups identical

Water all the plants following the watering schedule that was recommended on the seed packaging

Use the graduated cylinder to ensure the same amount of water is being given to both groups

Make sure all plants get the same amount of light

Step 4: Measure The Heights Of The Plants At The End Of Week 1

Measure the height of all twelve plants to the nearest cm. If a plant dies mark an x on the data table for that plant and write it in your notes

Use a calculator to find the average heights of the living plants in each groups

Calculate the difference in those average heights by subtracting the average height of the plants in the control group. Use this difference as a basis for comparison

Record measurement observations in your notes and the health of the plants such as leaf colors and size, wilting, unusual growth, brown spots, and any other marks you see

Step 5: Add Six Worms To The Soil Of The Experimental Group Of Plants

Write descriptive notes about the condition of the worms in your notes

Step 6: Measure The Heights Of The Plants At The End Of The Week 3

Repeat step 4

Step 7: Measure The Heights Of The Plants At The End Of Week 5

Repeat step 4

Step 8: Check The Health Of The Worms At The End Of The Study

Are the worms still alive?

Do they all seem healthy?

Have they changed in any way? If so list the ways changed

Are there any new worms

Be sure to write descriptive notes about their conditions in your notes

Step 9: Dispose Of All Material According To The Directions From Your Teacher

Week 1 (Before Adding Worms)

Week 3

Week 5

Plant 1

10cm

22cm

49cm

Plant 2

9cm

23cm

47cm

Plant 3

8cm

20cm

49cm

Plant 4

9cm

22cm

50cm

Plant 5

10cm

22cm

47cm

Plant 6

8cm

23cm

52cm

Control Group Average

9cm

22cm

49cm

Plant 1

8cm

24cm

50cm

Plant 2

9cm

28cm

60cm

Plant 3

8cm

26cm

49cm

Plant 4

8cm

25cm

53cm

Plant 5

8cm

27cm

58cm

Plant 6

7cm

26cm

60cm

Experimental Group Average

8cm

26cm

55cm

Difference In Average Heights

-1cm

4cm

6cm

Table answers go from left to right in the order I put