Mini-Unit:
Bean Seeds to Plants

Performance Standard B2, Level 2

Students use appropriate instruments to conduct simple experiments to answer a specific question about the natural or designed world.

Key Concepts and Skills

Students improve experimental design techniques.

Timeline

About two months.

Abstract

Students will investigate the effects of changing variables such as water, light, and fertilizer on the growth of a bean plant. Students will also closely observe bean seeds and plants in various stages of growth.

Materials

Activities

1

Read Tiny Seed by Eric Carle. Show students a variety of seeds. Ask students to describe the seeds. Ask students what they know about plant growth. Ask students what questions they have about how plants grow. List questions on chart paper and display in classrooms.

2

Soak different bean seeds in water overnight. Dissect seeds and observe with hand lenses. Record observations. Ask students what new questions they have about the seeds and how they grow. List questions on another sheet of paper. Work with students to organize their questions into the following categories:

• Questions we can investigate
• Questions we can research with our own sources
• Questions we need to ask an expert

As a class, choose one question to investigate. Work as a class to write a testable question that is appropriate for the level of students, materials available, etc. Discuss variables, how to control variables and how to manipulate a single variable. Brainstorm types of observations and measurements to make. Discuss ways to record data.

3

Pass out more seeds, bags, and wet paper towels and have students place seeds in bags with wet paper towel. Hang the bags in front of a window or under a grow light. Have students observe, measure, and record data every other day as seeds sprout. They should include measurement, sketches, and observations in their journals,

Additional Activity Ideas

• Teach students the elements of a technical report and have them write up their results and conclusions.
• Have a pot-luck with different bean and vegetable dishes.
• Have students research about the University of Alaska’s experimental farm activities to produce northern-adapted seeds.
• Research where the beans or Alaskan seeds they have grown come from.

Expanded Sample Assessment Idea

Students observe bean seeds and bean plants in various stages of growth and investigate the effects of changing variables (e.g., water, light, fertilizer) on the growth of a bean plant.

Procedure

Students will:

1. Review the questions about plant growth listed at the beginning of the lesson and add additional questions of interest to students.
2. Partner with someone who would like to ask the same question. (If a student has a question that no one else has, he or she may work alone.)
3. Design their own experiment using the same kind of seeds.
4. Set up a control plant, or plants, to which no changes are made.
5. Write or select a testable question.
6. Predict what they think results will be.
7. Design an investigation to test their prediction.
8. Collect data daily. Measure and document, in words and pictures, what happens to the seed and plant. Label the plant parts at all stages.
9. Repeat the experiment three times.
10. Analyze data and write/illustrate results and conclusions.
11. Students share with the class their experimental design, results, and conclusions; including problems they had with the investigation, and how they solved them.

Reflection and Revision

Discuss what they would do differently next time and why. Discuss how each group ensured that each test was fair (control variables, etc.)

Level of Performance

Student work is incomplete and incorrect. Although the investigation may consider questions about plant growth, it lacks an experimental procedure that reflects variables, controls, data collection or data manipulation.

Standards Cross-Reference
(Alaska Department of Education & Early Development Standards)

National Science Education Standards

Plan and conduct a simple investigation. As students develop, they may design and conduct simple experiments to answer questions. The idea of a fair test is possible for many students to consider by fourth grade. (Page 122)

Scientists use different kinds of investigations depending on the questions they are trying to answer. Types of investigations include describing objects, events, and organisms; classifying them; and doing a fair test (experimenting). (Page 123)

Different kinds of questions suggest different kinds of scientific investigations. Some investigations involve observing and describing objects, organisms, or events; some involve collecting specimens; some involve experiments; some involve seeking more information; some involve discovery of new objects and phenomena; and some involve making models. (Page 148)

Scientific investigations sometimes result in new ideas and phenomena for study, generate new methods or procedures for an investigation, or develop new technologies to improve the collection of data. All of these results can lead to new investigations. (Page 148)

Benchmarks

Results of similar scientific investigations seldom turn out exactly the same. Sometimes this is because of unexpected differences in the things being investigated, sometimes because of unrealized differences in the methods used or in the circumstances in which the investigation is carried out, and sometimes just because of uncertainties in observations. It is not always easy to tell which. (Page 6)

Scientific investigations may take many different forms, including observing what things are like or what is happening somewhere, collecting specimens for analysis, and doing experiments. Investigations can focus on physical, biological, or social questions. (Page 11)

Seek better reasons for believing something than “Everybody knows that . . . ” or “I just know” and discount such reasons when given by others. (Page 299)