What makes a seed?
Lesson 3 of 12
Objective: SWBAT identify questions that can be answered by dissecting a plant seed.
Today our Jack and the Beanstalk theme continues, as we explore seeds. Seeds come in many different packages, from seed pods to pine cones to a covering of fleshy fruit. But all seeds contain similar parts, including a seed coat or covering to protect the seed, an embryo (leaf beginnings), and nutrients.
Today's lesson will guide students to ask questions that might be answered as we dissect seeds together. I bring in a variety of seeds collected at local parks and also from seed packets at the local hardware store.
Because students are working to design the investigation, this lesson will be split over 2 days. On day 1, we will design our investigation and explore the outside of seeds. We will end by prepping for day 2. On day 2, we will dissect bean seeds to answer remaining questions. Then, we will infer and read about the function of different seed parts.
I begin by connecting to the prior lesson,
Friends, yesterday, we read Jack and the Beanstalk. What was the first step in the beanstalk life cycle? Right, the seeds!
Next, I connect to their prior knowledge about seeds through discussion.
What kinds of seeds do you know? What do seeds look like? What else do we know about seeds?
Students glue "What I Think I Know" about seeds into their Science Journal. My students all have a marbled composition journal dedicated as a Science Journal. I give them 5 minutes or so to write and draw what they know about seeds. While they work, I circulate and look for any misconceptions I'll need to address. I also look for interesting ideas that can be shared with the group.
I also review what students knew about seeds from the KWL chart we created on the first day of the unit.
I guide students here through designing an investigation of seeds. I ask students what questions they have about seeds, and if necessary, I ask questions that help guide them such as:
- What questions do you have about seeds?
- Do you know what is inside of seeds?
- Do you think all seeds are the same outside?
- Do you think all seeds are the same inside?
- What parts do seeds have?
As students share questions, I write them on post-it notes. Then, I ask, "How can we investigate seeds and answer our questions?"
Students usually suggest observing many different seeds. I help them design the investigation by asking, "What tools will help you observe?" Finally, if students have not suggested cutting the seeds open, I ask, "How can we see see inside of the seeds to see if they have the same parts?"
I display blank chart paper and record the investigation students design. I write at the top, "We will observe the outside and inside of seeds using magnifying glasses in order to answer our questions."
Next, I give groups of students multiple kinds of seeds to investigate. Students will work in groups to observe, draw, and record about the exterior of the seeds in their Science Journals. Student desks in my room are generally arranged in groups of 4. These students work together and share the same seeds. We work like this regularly in different subject areas, however, beforehand I always have students remind each other of the correct way to speak with one another. I say, "What will you say if someone has a seed that you need to observe?" "May I please see that seed when you're done?"
While students work, I circulate and assist where necessary. I also want to take their thinking beyond basic observation by asking, "Why do you think these seeds are different? Why do you think the outside of the seed is hard? How does that help the seed?" While circulating, I write notes to myself on a post-it note about which students observed something interesting or had good comments as we talked.
Here are some sample journals:
- Student journal: synthesized seeds with the idea of life cycles
- Student journal showing shared writing & her notes
- Student journal showing her ideas of sunflower seeds and life cycles
- Student journal labeling the cucumber seeds, brown pod, and more
- Student journal describing the marigold seed as "like a paintbrush."
For the end of Day 1, I bring students back to the rug in the Science Circle. Students share their observations and we discuss the extension questions as a class. If enough time remains, I record on the chart as students share. If not, the questions can be reevaluated at the beginning of Day 2. I facilitate a discussion of which questions have been answered, which we hope to answer by looking inside of the seeds, and which will not be answered by our investigation.
Finally on Day 1, prep for Day 2 by placing a few of each type of seed into a cup of water.
Day 2's investigation can possibly be done in small groups. However, I want to make sure the seeds split properly, so I choose to complete this part of the investigation together at the rug. I use my ELMO projector to magnify the seeds on the whiteboard as we cut and explore them. Students bring Science Journals and pencils to the rug to record as we investigate.
I use my fingernail to split the seed coat, or cover. I ask students to infer what the purpose or function of this external part might be. Inside, students can see the leaf embryo, or plant baby. Finally, we look around the embryo and decide what the rest might be.
I complete the same process with all of the seeds. Can students find the same parts inside?
What's so wonderful about these hands-on lessons is that they are truly lesson "seeds" that plant new ideas for children! Some of my students who were particularly intrigued chose to research bean life cycles in greater detail.
In closing, we reassess the questions we posed. Did our investigation answer our questions? What questions do we still have about seeds? Did we generate any new questions? Throughout the unit, I posted an "I Wonder" question vine on the back board. Our unanswered questions go there, and students may research them during free choice time in the small groups ELA time block.
This is also time to set up for the culminating engineering event. Students will need to know the parts of seeds and their functions. I have students glue a diagram of a seed into their Science Journals. We read the diagram together, and it tells the function of each part. Because it will be glued into their Science Journals, students will be able to refer back to these parts when we design safety equipment for Jack to climb the beanstalk. If time runs short after the investigation, I have students glue in and complete the diagram as morning work or as part of our morning message time on the following day.