Standard 2: Objective 1

Biology Standard 2: Objective 1

Title: My Desert Sponge

A Brief Description: In this activity students will take care of a sponge for 24 hours. They must make adaptations for the creature to stay hydrated. They will also make observations.

Materials needed: 18 standard size sponges, balance, cups, water, tape anything else students may think of.

Prior to Assessment: Students should understand the importance of water to cells and therefore living organisms

Time Needed: Two 50 minute class periods

Teacher Procedures: 1. Obtain required materials 2. Cut each sponge in half 3. Pass out student sheet 4. Read over purpose with students 5. Have them plan their modifications, list needed materials, make hypotheses etc (This portion of the lab will take around 20 minutes the first day) 6. Tell students to bring the needed supplies to support their sponges the following day 7. Pass out a sponge to each student, stress the importance of taking care of their sponge and ensuring its survival (I let the students name them and they think it is quite fun!) 8. The next day students should make their initial observations, modifications and data collections 9. This will probably take around 20 minutes, make sure students understand the importance of making observations at the appropriate times 10.Also make sure students know their sponge must be exposed to the environment for 4 hours during the 24 hour period. This represents the time the animal must leave its shelter to feed and obtain the energy required for survival 11.The following day students should mass their sponges and work on answering the lab questions.

Answers to Questions:

1. Answers will vary depending on the student’s adaptations 2. Answers will vary 3. –Dissolves important nutrients and gasses needed by our bodies –All chemical reactions must take place in water –It helps the body maintain a constant internal temperature 4. –An organism could become dehydrated and unable to obtain the energy that it needs –The organism could die from lack of water 5. Answers will vary 6. Water is the universal solvent-it dissolves needed gasses and nutrients. Water has a high heat capacity to help maintain a constant internal temperature so that reactions can occur. Water has cohesive properties which allow for surface tension and capillary action. Finally water has adhesive strength which is important for plants and animals. 7. It is similar in that the organism has an adaptation to conserve water, the sponge will lose water if steps are not taken to conserve it. It is different in that the sponge is not alive and cannot drink water and also that the sponge is not losing energy and water through cellular process like respiration etc. 8. All living organisms require water. The number of organisms in an environment is dependent on the amount of water available to sustain them.

Conclusions: Answers will vary but they should be indepth and show understanding by the student.

Sample Scoring Guide:

Prelab Completed (materials through experimental design): 10 points Observations detailed and complete: 20 points Questions answered correctly: 16 points Conclusions are thoughtful and complete: 9 points My Desert Sponge

Name:______Period:______

Purpose: The small sponge you have been given represents your own desert organisms. Organisms need water to sustain life. In the desert animals have adapted to conserve water. You must conserve the water in your sponge. Over a 24 hr period you must take care of your creature in a manner that will best achieve this goal using only natural materials. Your creature must be out in the open for at least 4 hrs during the 24 hr period to feed.

Materials: sponge balance water

Independent variable:

Dependent variable:

Hypothesis: (If and then)

Experimental Design: (pictures and your plans and modifications)

Procedures:

1. Obtain a small sponge from Mrs. Davidson 2. Weigh your sponge on a triple-beam balance 3. Record mass in grams 4. Make modifications to your creature 5. Record observations every 2 hrs 6. Record any changes you make to your creature 7. Mass your sponge at the end of 24 hrs and record

Data and Observations: Quantitative Data

Beginning mass: ______Ending mass: ______

Qualitative Data

Time (hrs) Observations

Initial

Before you go to bed at night

When you wake up

Final Observations in class

Analysis: 1. List 3 adaptations you made to your sponge and explain your reasoning behind each one.

2. Explain the success or failure of each of your adaptations.

3. Explain 3 reasons why water is important to organisms? 4. Explain 2 consequences to an organism if it could not obtain enough water?

5. Compare your observations of your “creature” as compared to a real organism. What does each observation correspond to in real life? (Example: sponge drying up: organism dehydrating)

6. What are 4 important properties of water? Why are each of these so important?

7. How is this lab similar and different to animals in a real environment? Explain 4 ways.

8. How can water act as a limiting factor in an ecosystem?

Conclusions: (3 concepts you learned in complete sentences)