Biologist ______Date ______

Sponge Capsules: Scientific Method Lab

Purpose – To develop a hypothesis, test a hypothesis, collect data, analyze data, and compose a lab conclusion.

Background – In the lab you will be given 2 gelatin capsules that contain sponge animals that are common toys usually labeled as “magic capsules.” The animals will grow when placed in water. Consider the following questions about sponge animals.

Does the temperature of the water affect rate of growth?

Does stirring the water affect the rate of growth?

Does the type of water, salt or tap, affect the rate of growth?

Experiment – Choose one questions and develop a hypothesis. Remember to state your hypothesis in a complete sentence and make sure it is testable.

Hypothesis ______

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Materials – 2 beakers, water (plain, warm, salt and/or sugar), 2 sponge capsules (same color), spoons, stop watch.

Procedure –

1.  With a lab partner, place enough plain tap water in one of the beakers to fill it approximately 2/3 full. Fill the other beaker to the same volume with salt water, warm water, or sugar water. Label each beaker as either CONTROL or EXPERIMENTAL.

The CONTROL beaker contains ______water.

The EXPERIMENTAL beaker contains ______water.

The Independent Variable is ______.

The Dependent Variable is ______.

2.  Have your stopwatch ready to go. Place one sponge capsule in the first of the 2 beakers and begin timing. Stop the timing when the sponge animal has stopped growing. Repeat for the second beaker.

3.  Record the time for each sponge capsule.

CONTROL = ______sec.

EXPERIMENTAL = ______sec.

4.  Enter your data onto the class data table.

Lab Conclusion

1.  State the problem (observation/question) asked at the beginning of the lab.

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2.  Restate your hypothesis

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3.  Class Data – Table 1: Rate of Growth of Sponge Capsules in Difference Environments (sec.)

GROUP / CONTROL / Warm Water / Salt Water / Sugar Water
1
2
3
4
5
6
7
8
9
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12

4.  Graph the data from the table on a sheet of graph paper.

5.  Write your conclusions. Your conclusions should answer the experimental question (problem/observation asked at the beginning of the lab). Use your data to support your answer. Suggest a reason why the sponge animals behaved the way they did.

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