Lab: How is the Germination of Seeds Affected by Abiotic Factors?

Transcription

1 Name Date Lab: How is the Germination of Seeds Affected by Abiotic Factors? Introduction: Ecosystems are affected by a variety of factors. Biotic factors are the living components of an ecosystem. Abiotic factors are the nonliving components of the ecosystem. The organisms in an ecosystem are influenced and affected by this combination of biological and physical factors. Together these factors determine the survival of organisms and the general health of the ecosystem. In this lab, you will determine how two abiotic factors affect the germination of 2 different seeds. Purpose: 1. To determine the effect of certain abiotic factors on the germination of seeds. 2. To describe the relationship between biotic and abiotic factors. Materials: Radish Seeds Rice Seeds Potting soil Sand Graduated cylinder Plant growth containers (ice trays) Masking tape Procedure: 1. Obtain two ice trays. In the first tray, fill all compartments with sand. In the second tray, fill all compartments with potting soil. Try to place approximately the same amount of soil or sand in each compartment. 2. Start with the ice tray containing only sand. You are going to plant radish seeds down one side of the ice tray and rice seeds down the other side. Make small holes in the sand using a glass stirring rod, your pencil, or other similar object. Make two holes in each compartment and place a seed in each hole. Fill in the hole, covering the seed with sand. Note: Remember to plant only radishes all the way down one side of the ice tray and only rice all the way down the other side of the ice tray. 3. Place a piece of masking tape on the tray with your name written on the masking tape. Label one side of the tray radish and the other side of the tray rice. 4. Repeat steps 2 and 3 using the ice tray containing potting soil. 5. Now you must water your seeds. All seeds should receive the same amount of water. Your teacher will let you know how much water to place in each compartment. Use a graduated cylinder to measure the water and place the water in each compartment. My teacher said to use this much water: 6. Place the trays in a sunny location. 7. Clean your area as instructed. Wash your hands with soap and water. 8. Answer questions 1 5 now. 9. In the days ahead, make observations and water your seeds as instructed by your teacher.

2 Analysis Questions Day 1: Answer the following questions immediately after planting your seeds. 1. Distinguish between biotic and abiotic factors. Give examples for each. Biotic: Abiotic: 2. What two abiotic factors are being tested in this experiment? 3. Why was it important to place the same amount of soil/sand in each compartment and water each compartment with the same amount of water? 4. What is your hypothesis for this experiment? Begin your hypothesis with, I predict that. 5. Are biotic and abiotic factors dependent or independent of each other? Explain your answer.

3 Data Table: We will make observations of our seeds/plants every two days until a conclusion can be reached. Record your observations in the table below. Possibilities of what to include in your observations: (1) Condition of the soil Which soil type is drying faster? (2) Which seeds are germinating first? (3) How many seeds have germinated on each observation day? (4) Once seedlings appear, do they appear healthy and robust, or barely alive? (5) Does the soil type seem to have an affect on the germination of the seeds? DAY OBSERVATIONS Day 2 Day 4 Day 6 Day 8 Day 10 Day 12 Day 14

4 Mid- Point Analysis Questions: 6. Can you see any pattern or trend in the seed germination rate in the two types of soil? 7. At this point, do your observations seem to support or disprove your predictions stated on the first day of the experiment? Explain your answer. Final Analysis Questions: 8. In which type of dirt (sand or soil) did the rice grow the best? 9. In which type of dirt (sand or soil) did the radishes grow the best? 10. How did the amount of water used affect the germination of each type of seed? 11. Did the germination of the seeds depend upon the abiotic factors? Explain your answer. 12. If you were a radish farmer, what conditions would you provide to insure the best crop yield? Are these things biotic or abiotic?

5 13. Consider the predictions you made on the first day of this experiment. Given your predictions and the data obtained during the lab, state your conclusions for the experiment. For example, you might include statements such as, I predicted XYZ and/but the data shows..