CSTA Classroom Science

Second Grade Seed Dispersal Engineers!

By Nila Arensberg, Kristi Drake, Amanda Cloutier, and Pete A’Hearn

It’s time for the big test! Which seeds will stick to the animal’s fur?[/caption] 

Second graders had worked hard on their engineering designs to make a lima bean that would be transported by sticking to an animal’s fur. The used wires, tape, Play-Doh©, staples, paperclips, foil, and paper to make their seed dispersal attachments.

This was the highlight of a lesson designed and taught by a team of second-grade teachers in Palm Springs Unified School District as part of the California Next Generation Science Standards K-8 Early Implementation Initiative. Our team used a lesson study process, designed by the K-12 Alliance, called a Teacher Learning Collaborative (TLC). As a team, we know that in elementary school, and especially early elementary, we need to find the strong connections between science and the Common Core standards. We set out to design an engaging lesson that would teach science and provide students with opportunities to engage in speaking and listening, writing, and reading.

Our team had worked on second grade physical science earlier in the year and we were eager to try our hand at the second-grade life science standards. We decided to focus on the needs of plants and used the conceptual flow tool to get our heads clear about what concepts, practices, and crosscutting concepts would belong in a unit about the needs of plants (if you’ve been to a CA NGSS Rollout you have experienced this tool and process).

Turns out, there is a lot of content for this topic. Plants need soil and sunlight, water and air, but they also need help from animals by assisting with pollination and dispersing seeds in locations where they will find the right conditions for growth. We planned for students in this unit to think in terms of Structure and Function and Cause and Effect. They would make models and conduct investigations as a way on understanding the concepts. After getting clear on the three-dimensional content, we focused in on this Performance Expectation for the lesson we would design:

2-LS2-2: Develop a simple model that mimics the function of an animal in dispersing seeds or pollinating plants.

Image source: http://pgtnaturegarden.org/2012/09/droughts-arent-all-bad/[/caption] 

We tried to think about a good way for students to demonstrate their understanding of seed dispersal. We studied various curricula and resources to look for ideas. Nila came up with the idea that we could have the students try to design a seed structure that we could test with a stuffed animal to see if it would stick to an animal’s fur. After testing the designs, students could practice writing an argument about whether their structure was successful or not. Now that we had a good idea about where the lesson was going, we could design a sequence that would lead them to the seed test.

We decided to engage the students with the phenomenon of a dog covered with seeds. We asked the students to talk to a partner about why the seeds stick to the dog. We were hoping for responses both about the structure of the seeds (Structure and Function) and the idea that animals help to move seeds around (Cause and Effect). We had follow-up questions planned if students didn’t address both ideas.

Students observing seed structures.[/caption] 

Then it was time to let kids explore some real seeds. We gave the kids some desert seeds to study under a hand lens and then also gave them cotton balls that they could use like an animal to “walk” over their seeds and see which ones would stick. The hand lenses allowed them to closely observe the structures that functioned to allow the seeds to stick to the cotton balls.

Students using sense-making notebooks.[/caption] 

Science notebooks were used for drawings and written descriptions of the seed structures. We had some students share their notebook entries using the document camera. Students shared structures like hairs, spikes, hooks, and fuzzies.

Now for some reading to help reinforce the idea. We chose a short passage about how seeds travel and grow that expanded the idea about seed dispersal with other means like ending up in animal scat and being carried on the wind. Students recorded new ideas from the reading in their notebooks to show their understanding of both the hands-on exploration and reading (explain).

Now it was time for the engineering design challenge as an elaborate! We showed students the lima beans and showed how we would test their designs by walking the animal over their seeds. The lima beans sure did not stick! We also showed kids the materials that would be available for the building.  Students began by brainstorming designs in their notebooks.

[gallery type="rectangular" ids="13624,13625"] 2 IMAGES, NO URL

They could choose to work with a partner or on their own. Once they had a design idea, we gave them materials to start building.

These seeds stuck![/caption] 

Then finally the big test. Seeds were sorted into a pile of those that worked and those that didn’t. We then asked students to write a claim in their notebooks about whether their design worked or didn’t and support it with evidence.

As always in a lesson study, we teach the lesson as a team debrief the lesson by examining student work for evidence of the lesson’s effectiveness. This debrief informs changes to the lesson that are warranted. One change was obvious: don’t include balloons in the materials. They don’t work but are way too exciting for second graders not to want to use. Their inclusion just distracted from the designs. We also shortened the reading to the essential pages of the book.

Analysis of the student work revealed a bigger concern: the claims were poorly written and the students didn’t really have any idea of what evidence to use. We decided that we needed to include a class discussion of what worked in the designs and what didn’t. This was done by sorting the seeds under the document camera and having a class discussion. We charted ideas from the discussion on the board. We also provided sentence frames (Table 1) for the writing to help students with the types of evidence that would support a claim.


We taught the lesson a second time and could see from the designs and the student work that the adjustments had a big effect. The students walked away with a deeper understanding of seed dispersal, structure and function, design, and using evidence. As teachers, we learned a lot about how an NGSS lesson could incorporate engineering into science learning. We also reinforced what we already knew - in teaching, little changes can make a big difference!

Nila Arensberg is a 2nd grade teacher at Bubbling Wells Elementary School, PSUSD, a Teacher Leader in the CA NGSS K-8 Early Implementation Initiative, and a member of CSTA.

Kristi Drake is a 2nd grade teacher at Rancho Mirage Elementary School, PSUSD, a Teacher Leader in the CA NGSS K-8 Early Implementation Initiative, and a member of CSTA.

Amanda Cloutier is a 2nd grade teacher at Bubbling Wells Elementary School, PSUSD, a Teacher Leader in the CA NGSS K-8 Early Implementation Initiative, and a member of CSTA.

Pete A’Hearn is a K-12 Science Specialist in PSUSD, a Project Director for the CA NGSS K-8 Early Implementation Initiative, and the Region 4 Director for CSTA.



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