Teacher Notes

Plants and Pollution

Student Laboratory Kit

Materials Included In Kit

Fertilizer solution, 10%, 200 mL
Salt solution, NaCl, 10%, 200 mL
Soap solution, 10%, 200 mL
Vinegar solution, 10%, 200 mL
Filter paper, 300 sheets
Petri dishes, 80
Seeds, radish, 2,500

Additional Materials Required

Water, distilled
Graduated cylinder, 10-mL
Marker

Safety Precautions

Seeds are routinely treated with mold-inhibiting chemicals to help preserve them. Wash hand thoroughly with soap and water before leaving the laboratory. Wear chemical splash goggles, chemical-resistant gloves and a chemical-resistant apron. Please review current Safety Data Sheets for additional safety, handling and disposal information.

Disposal

Please consult your current Flinn Scientific Catalog/Reference Manual for general guidelines and specific procedures, and review all federal, state and local regulations that may apply, before proceeding. All materials may be thrown in the trash or flushed down the drain according to Flinn Suggested Disposal Methods #26a and #26b.

Teacher Tips

  • Enough materials are provided in this kit for 30 students working in pairs or for 15 groups of students. The completion of this laboratory will require parts of at least four class periods over a several week period. Petri dishes from Part I of the activity should be rinsed thoroughly and used in Part II of the activity.

  • A variety of questions can extend these activities into very interesting and easy projects for students to complete. A few questions might include:

    1. Can the seeds from Part I that did not germinate be washed and still germinate?
    2. If seeds are allowed to germinate and then treated with the chemicals, will it affect their additional growth?
    3. Do other seeds have the same sensitivity as radish seeds to these chemicals?
    4. What other pollutants can affect radish seed germination?
    5. Can pollutants “stunt” plant growth and affect its biomass production? (Will one get scrawny radishes?)

Correlation to Next Generation Science Standards (NGSS)†

Science & Engineering Practices

Asking questions and defining problems
Planning and carrying out investigations
Analyzing and interpreting data

Disciplinary Core Ideas

MS-LS2.A: Interdependent Relationships in Ecosystems
MS-LS2.C: Ecosystem Dynamics, Functioning, and Resilience
MS-ESS3.C: Human Impacts on Earth Systems
HS-ESS3.C: Human Impacts on Earth Systems
HS-LS2.C: Ecosystem Dynamics, Functioning, and Resilience
HS-LS2.A: Interdependent Relationships in Ecosystems

Crosscutting Concepts

Patterns
Cause and effect
Scale, proportion, and quantity
Stability and change

Performance Expectations

MS-LS2-4. Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.
MS-LS2-1. Analyze and interpret data to provide evidence for the effects of resource availability on organisms and populations of organisms in an ecosystem.
HS-LS2-2. Use mathematical representations to support and revise explanations based on evidence about factors affecting biodiversity and populations in ecosystems of different scales.

Sample Data

Germination results are very dramatic in this simple experiment. In Part I, only seeds in plain water are likely to germinate at all—radish seeds are very sensitive to their surroundings. Student data will vary.

Part I. Seed Germination and Pollution

{10423_Data_Table_2}

Answers to Questions

Part I. Seed Germination and Pollution

  1. Which Petri dish had the greatest rate of germination? Explain.
    Results will vary but most likely Petri dish 1.
  2. Do changes in the environment of a radish seed affect its ability to germinate? What data supports your answer?

    Results will vary but will most likely give a strong yes answer due to variation in germination rates.

  3. What are the real environmental pollutants that might be simulated by treatments 2–5?

    #2 Acid rain; #3 detergents and other cleaners; #4 road salt and other chemical spills; #5 fertilizers and other plant herbicides and pesticides.

Part II. Pollution Sensitivity
  1. Describe your experimental design and procedures.

    Designs will vary.

  2. Experimental results. Use charts or graphs as appropriate.

    Results will vary.

  3. Discuss your experimental results.

    Discussions will vary.

Recommended Products

Item No. Description
FB1615 Plants and Pollution—Student Laboratory Kit
W0001 Water, Distilled, 4 L

Student Pages

Plants and Pollution

Introduction

Plants need moisture and other key ingredients to grow vigorously and healthy. How do environmental pollutants affect the vigor and growth of plants?

Concepts

  • Germination

  • Concentration
  • Pollutant

Background

We read about pollution in our newspapers and hear pollution stories on the news with a certain degree of regularity. What is pollution and why are these stories so common? What are the consequences of pollution?

Pollution has been described as the poisoning of our environment. It is an undesirable change in the physical, chemical, or biological characteristics of air, water, soil or food that can adversely affect the health, survival or activities of living things. Pollution can take on many forms and have many varied consequences.

Many questions need to be answered for every potential pollutant. A specific pollutant needs to be analyzed in many ways when it is discovered. Three general issues are always considered: (1) What is the chemical nature and how toxic is it to living things? Does it affect all living things equally? (2) What is its concentration in a specific area and can it be diluted to decrease its toxicity? (3) How persistent is the pollutant? Does it break down or decay over time?

Some pollutants only affect a small number of organisms—they are said to be highly specific. Some species may tolerate certain pollutants while other species are susceptible to damage from any pollutant. Some pollutants work very quickly on organisms while others work very slowly. Because of these variations, the study of pollutants can be very complex and answers are not always easily formulated.

An example of short-term pollution includes the application of salt to melt ice off our roads. Pollution with longer term consequences, on the other hand, includes the application of fertilizers or pesticides, which may affect plants only after a much longer period of time. In this activity, very specific consequences of different pollutants on one plant species will be observed. Further testing would be required to demonstrate the consequences of similar treatments on other species.

Materials

Fertilizer solution, 10%, 3–10 mL
Salt solution, 10%, 3–10 mL
Soap solution, 10%, 3–10 mL
Vinegar solution, 3–10 mL
Water, distilled
Filter paper, 5–10
Graduated cylinder, 10-mL
Marker
Petri dishes, 5
Radish seeds, 50–100

Safety Precautions

Seeds are routinely treated with mold-inhibiting chemicals to help preserve them. Be sure to wash hands and work areas thoroughly upon completion of the laboratory work. Wear chemical splash goggles, chemical-resistant gloves and a chemical-resistant apron.

Procedure

Part I. Seed Germination and Pollution

  1. Place a piece of filter paper into the top of five Petri dishes.
  2. Label the Petri dishes 1–5. Use a 10-mL graduated cylinder to pour 5 mL of specific liquids on the filter paper until the filter paper is completely soaked. Evenly space 10 radish seeds on the soaked filter paper. Cover the seeds with another piece of filter paper soaked in the same solution.
{10423_Procedure_Table_1}
{10423_Procedure_Figure_1}
  1. Place the bottom of the Petri dish on top of the soaking seeds. Set the Petri dishes aside for three days where they will not be disturbed.
  2. After three days, open the dishes and examine the seeds. Record the percentage of germination (sprouted) seeds in each dish on the Plants and Pollution Worksheet. Answer the questions for Part I on the worksheet.

Part II. Pollution Sensitivity

  1. Select one of the treatments for Part I that resulted in no germination.
  2. Design an experiment to determine the lowest sensitivity of radish seeds to the pollutant. Describe your experimental procedure on your worksheet.
  3. Conduct your experiment, record your results and discuss your results on the Plant Pollution Worksheet.
  4. Report your findings to your class as directed by your instructor. Hold a class seminar on pollutants and radish seed germination.
  5. Consult your instructor for appropriate disposal procedures.

Student Worksheet PDF

10423_Student1.pdf

†Next Generation Science Standards and NGSS are registered trademarks of Achieve. Neither Achieve nor the lead states and partners that developed the Next Generation Science Standards were involved in the production of this product, and do not endorse it.