Teacher's Guide: Measuring Germination Rates

Introduction

This lesson was developed as part of a National Science Foundation funded project called Digital Desert Library. This project is a collaboration among NMSU's College of Agriculture and Home Economics and College of Education and the Smithsonian's National Museum of Natural History.

This activity allows students to investigate the rate of seed germination. Students do the activity as a comparison of temperature effects, and may investigate other factors that affect germination rate.

Content Areas and Grade Levels

This activity is appropriate for grades 3 through 8. Science skills of observation and data collection are exercised. The results can easily be integrated into a spreadsheet and graphed on the computer.

Curriculum Standards

National Science Education Standards:

Content Standard A: K-4 - Science as Inquiry.
Content Standard C: K-4 - Life Science.
Content Standard A: 5-8 - Science as Inquiry.
Content Standard C: 5-8- Life Science.

New Mexico's Content Standards and Benchmarks:

Standard 5: Abilities to do scientific inquiry.
Standard 6: Process of scientific inquiry.
Standard 11: Know and understand synergy among organisms and the environments of organisms.

National Council of Teachers of Mathematics Curriculum and Evaluation Standards:

Standard 2: K-4 and 5-8: Mathematics as Communication
Standard 3: K-4 and 5-8: Mathematics as Reasoning
Standard 4: K-4 and 5-8: Mathematics as Connections

Other standards may be touched upon. Check with the National Science Education Standards and New Mexico's Standards and Benchmarks. Also, this activity promotes cooperation and categorization skills, comparison, and collaborative creative production.

Implementation

This activity requires two to three weeks of observation with approximately 30 minutes every other day for data collection. Students can be put into groups of three of four or left as a class group. Small groups are preferred. Students need time for discussion both before the activity, such as the day before, and after the activity. Results can be displayed in several ways, from simple construction paper to detailed diagrams in a draw document on the computer. Other methods of presentation are given in Presentation Methods and Ideas.

Procedure

Introduce students to the idea of germinating seeds. Discuss the definition of 'germination' and ask the students what they think might influence how fast the seeds sprout. They might suggest light and dark, the amount of water or moisture in the environment, or the temperature at which the seeds are germinated. This lesson suggests changing only the temperature at which seeds germinate and keeping other conditions the same. Ask the students what effects changing the temperature might have on seed germination. If some students want to try changing the amount of light, or adding fertilizer to the water, they could be encouraged to try additional experiments.

Divide the class into teams of three or four. Provide each team member with a task and give each team the appropriate materials.

Two Petri dishes with covers or large clear plastic ziplock bags
Paper towel or filter paper for each container
30 seeds for each container (or as many as you can provide without overcrowding the container)
Two thermometers
Science journals or notebooks
Pipettes or syringes for delivering water to the containers
Tweezers or tongs for removing the seeds that germinate
Paper cups or pots for planting the seeds that germinate
A computer with Spreadsheet software

Method

Assign students groups
Provide all the necessary items
Assist students in preparing the containers
Encourage students to follow directions carefully
Set up an observation schedule or guide students as they plan one
Direct the dialogue through Socratic questions, maintaining lesson themes
Allow students time to create displays or presentations of their findings
After the activity, have groups share with one another their initial thoughts and questions and what discoveries they made.

Preparation and Management

This lesson is best done as part of a unit on the study of plants. Students should have some background knowledge of factors that influence plant growth. The teacher should be sure the students know how to collect data and keep accurate records. Students should be familiar with the spreadsheet application available for this activity. They should be comfortable entering data in worksheets and generating graphs.

This is an excellent lesson for the one -four computer classroom. Student groups can take turns entering data into their spreadsheets during the day. Since data is collected by pencil and recorded in journals or notebooks, it can be easily transferred to computer any time. We suggest you assign students in groups of four so that two students can monitor the cool location and two can monitor the warm location.

Entry Level Skills and Knowledge

Students will need some prior experience with using spreadsheet applications on the computer. If no computer is available, graphing can be done on paper using line graphs drawn on large poster board. See Creating a Paper Graph.

Teachers will need some experience in organizing students into groups and keeping them on task. They will also need access to the computer software. To manage the time element of this activity, teachers need to make sure students are observing and recording the correct data. Students may need help in constructing graphs and spreadsheets.

Resources

Additional resources of information may be found at the following sites:

We want to acknowledge the direction of Dr. Norm Lownds in designing this experiment and in other work we have done with teachers and plants. He is a professor, and curator of the 4H Children's Garden, at Michigan State University.

Evaluation

It is important that students do careful measurements and keep accurate records. As the students begin to discuss their work and analyze the results of their experiments, you will be able to judge how carefully they did this experiment. Each team can discuss its findings. Here are some questions you can pose to them. Be sure to listen to all participants as their opinions may vary.

What worked well in your experiment?
What were the most difficult parts of the investigation? What problems did you have and how did you solve them?
Based on your data, how did temperature affect the number of seeds that germinated?
Based on your data, how did temperature affect the rate of germination (how quickly/slowly)?
Was there a difference? What caused it, in your opinion?
Predict what would happen if the temperature was even cooler or warmer than in your experiment.

As a class, you can look at the graphs generated by each team and discuss the following:

Do the graphs ad data seem similar or different?
If the graphs seem to point to different conclusions, how could you explain what happened?
Based on every team's data, how did temperature affect the number of seeds germinated?
Based on every team's data, how did temperature affect the rate of germination?
How does your information apply to the real world: farming, planting, weather?
What advice would you give a new farmer based on your findings?
What other kinds of experiments would you like to do with seeds or plants?

Make sure you have the students display their experiments' process and findings. Display boards used for science fair projects would work well. Have them use another form of presenting their findings to the class by choosing one or more of the Presentation Methods and Ideas.

Conclusion

This activity teaches observation, investigation, and inquiry. It applies to topics in earth and life science. It looks at temperature and moisture (weather topics), germination (life science), and changing/controlling variables (research skills). It is applicable to all grades but best served in third through eighth. The activity can be integrated with gardening and other activities by placing germinated seeds in pots or garden plots.

This activity was created by Dr. Norm Lownds, Michigan State University, and Dr. Karin Wiburg, New Mexico State University.