Plant Parts: The Stem
Lesson 4 of 15
Objective: SWBAT explain how the stem works and its functions.
Setting the Stage
Advanced Preparation: celery stalks with leaves, white carnation flowers, asparagus, food coloring, plastic glasses.
The students will start the lesson by going outside to find different examples of stems. The class will then gather and discuss their findings and talk about the similarities and differences of the stems they collected. The class will then set up an experiment with a variety of stems to discover how a stem delivers water and nutrients to the rest of the plant.
Our district expects students to understand that a plant is a system that goes through a natural cycle and the parts help the plant survive and reproduce. By focusing on the parts and needs of a plant, I can teach them how the parts have a role that helps a plant get the things it needs to survive. The unit will end with the class spending 4 days int eh school garden and applying their learned knowledge to the work being done in the garden.
Students demonstrate their understanding of Reproduction by…
I gather the students on the carpet and ask them to sit in a circle.
"Today we are going to talk about another plant part called the stem. The function of the stem is:
- Support for and the elevation of leaves, flowers and fruits. The stems keep the leaves in the light and provide a place for the plant to keep its flowers and fruits.
- Transport of fluids between the roots and the shoots
- Storage of nutrients
I want you to head outside and find two or three different examples of stems. If they are too big to pick, I want you to take a mental picture so that you can talk about it."
I then have the students go out onto the playground to find their examples. I teach in a school that is surrounded by fields and woods. Finding a variety of stems will not be a problem. You will need to take this into consideration as you plan the lesson.
Once the students are finished, they gather back in a circle and share their findings. After each student shares their stems, I ask them to tell me how they are all similar. I want to establsih that the stems are tube like.
"As we have discussed, stems hold up other plant parts that are above ground. Stems also carry food and water from the roots through the leaves. Now we are going to conduct and experiment to learn about how stems carry food and water. You will each be given a piece of celery, asparagus, and a flower. You will take three plastic cups and fill them up with water. Then you will place six drops of food coloring into each cup. Then place each stem into a different cup. Then fill out the Stem Study sheet for each cup and stem. You will then fill out part 1 of the sheet. You will fill out part two tomorrow, when you arrive to school."
The stems will need to soak over night in the colored water. They will use their morning writing time to explain what happened and finish filling out the Stem Study sheet.
I have the students gather on the carpet and make a circle for a quick discussion about their predictions.
"Now that you have all made your predictions, who can tell me what they think will happen?"
I facilitate the conversation with a focus on the students predictions and the "why" of their thoughts. I want to see who is already demonstrating an understanding of how a stem works and that it distributes water and food to all parts of the plant. The celery stalk leaves will be a great example of this as well as the white carnation.
I will not evaluate the student work until the following day. The students will need to complete their observations after the stems have soaked in the colored water over night. Once they are completed, I will look to see if students can explain what happened and why and of they can explicitly explain the function of a stem. I have included a student's response to both pages of the Stem Study sheet (Stem Study 1 & Stem Study 2).