Seeds on the Move
Lesson 3 of 4
Objective: SWBAT to identfy seed dispersal attributes and explain why seed dispersal helps plant survival.
Question for the Day
Connection to: NGSS 2-LS2 - Ecosystems: Interactions, Energy, and Dynamics and ETS1 - students make sketches to show how the shape or attributes of a seed help its function for seed dispersal.
Students learn about the different ways plants disperse their seeds, and how aspects of nature, wind or water and animals assist with dispersal. Students watch videos to observe and identify different seed structures that assist with the function of seed dispersal.
Posted on the board: Why might seeds grow better if they move away from their parent plant? (show class log book)
We start science on the rug together. Students know that when they return from lunch, we meet on the rug to read our 'science question for the day'. I have established this routine with the kiddos to keep transition time short and effective and redirect student's attention back to content while allowing time for focused peer interaction.
Students read the question and to turn to their shoulder partner to discuss. I listen to conversations. Most students share that plants need more space. After the demonstration below, I check that students can articulate that seeds are dispersed more sun and rain
I demonstrate with an umbrella (parent plant), flashlight (sun), spray bottle with water (rain) to show why seeds have a better chance of growing if they disperse.
I ask for a volunteer to hold and stand under the umbrella. “This is the parent oak tree.” (Student holding the umbrella). Then I place an acorn at the base of the tree. “When the sun shines will the acorn get the sun it needs to sprout under the shade of the oak tree?” (Use the flashlight to shine down on umbrella) “Will the acorn get enough of the water it needs under the shelter of the oak tree?” (spray the rain).
Activity adapted from Project Learning Tree.
“Remember in our last lesson, we learned that inside a seed is a baby plant, an embryo. The plant has put a lot of work, energy into making the seed. So many plants have ways to disperse their seeds."
I read the word and definition with the kiddos and we say the word again. This time we act like we are throwing seeds out. I am providing a visual and action which gives my learners multiple entry points to recall the term disperse. It also helps to connect the printed word to the auditory, to scaffold my emergent readers.
"So why are seeds dispersed? What do they need? Please turn and share."
I listen in to the conversations to hear if students can transfer information from the demonstration.
"Plants have placed a lot of energy in the seed to make sure the embryo, the baby plant will grow. The plant made the seed cover and food, the endosperm, for the embryo. Now the plant designs one more thing for the seed, a way to send the seed out in the world so that it will land in a good place to grow."
"Plants that have ways to disperse their seeds make it possible for more seeds to grow into new plants. Plants that do not have an effective way of dispersing their seeds will not have a good chance of survival.“
“Botanists, today we will look at videos and pictures that show us the ingenious ways seeds are dispersed. Before you go back to your desk, please turn and tell your partner what the word disperse means. “
Viewing and Diagraming
After students return to their desk. I pass out the seed dispersal lab that students will use to write information as we watch the video.
"Botanists, today we will watch 4 ways that plants disperse seeds. I want you to look closely at what the seeds or plant have that help the seeds be dispersed. You will make diagrams to show the seed attributes that help it be dispersed in different ways."
"Let's review what a diagram is, it has an accurate sketch with labels, that give the viewer information. I show them the lima bean diagram with criteria we made in our last science lesson.
"For each box you will be drawing a seed, so the word seed should be one of your labels." I write seed on the board under 'Diagram Labels'.
"You will also need to use labels to describe the seed attributes that help it be dispersed in a certain way. Remember when you sorted the seeds and you wrote attribute words to describe how the seed was sorted. Now you are observing the attributes of the seed that help it to be dispersed."
I am connecting students' schemas to a prior lesson to help them connect the vocabulary word, 'attribute' to a new lesson.
I write 'seed attributes that help the seed to be dispersed', under Diagram Labels'. Writing what should be labled on the board supports my visual learners.
I make a diagram on the class log book and ask for input on the parts we should label as students work on their diagram. This helps to establish my expectations for their diagrams and to develop the vocabulary we will choose to use in our labels.
The first 1:23 minutes of the second video shows other seed designs that take advantage of the wind/gravity. Sound effects are added to the video as the seeds move in slow motion, you may want to tell students that the seeds do not actually make these sounds. I will pause the video after 1:23 to provide students time to add these seed designs to their wind box.
I point out that seeds are using lift to keep from falling to the ground right away. I ask students to point to the part of the diagram that helps the seed get this lift.
Seed Mechanics - Before I show the next segment of the video, I point out that there is a blank line on their worksheet for this seed dispersal method.
"I thought you could help me label this seed dispersal method after we watch the video. Then we will write our 'title' for this method in the blank."
After I show this next segment, I ask how are the plants dispersing seeds and what should we call this seed dispersal method.
I could have said we will use the lablel 'mechanical' or 'self', but I want students to take ownership of their learning and begin to create labels that make sense for them. Through the discussion of what to name this seed dispersal method, students begin to integrate the parameters for this type of dispersal within their own schema.
Time is given for students to draw and label example(s) of mechanical dispersal.
Water Dispersal: The next video we watch is a seed dispersed by water. After the video I ask students, "How was the seed dispersed? How would we describe this water? stream?
I touch on this topic to get an idea for student's background knowledge for what they know of water. Learning about where water is on the planet is a future unit
What helped the seed be dispersed by water? " (seed coat, shape of the seed) Then time is given for students to draw and label example(s) of water seed dispersal.
"The next seed dispersal method has two parts. Animals help in 2 ways with seed dispersal. Show me with your thumb if you have an idea how animals may help with seed dispersal. Wow I am seeing a lot of thumbs, will you take a moment and share your thoughts with your table group."
Seed Dispersal Via Animal: Then I show the video segment that shows seeds 'hitching a ride' on animals or humans. Before sketching, I ask students what did these seeds have? I also mention that an engineer designed velcro after looking at the seeds that would stick to his sock.
To illustrate the idea that seeds are eaten, I show different fruit, i.e. banana, cucumber, tomato, strawberry under the document camera and point out the seeds.
"Many plants make yummy fruit that animals like to eat, but the seeds are not broken down in the our stomach or the animals' stomach because of the seed coat. The seed is removed from the animal when it poos, which has nutrients for the seed to grow in. What animals can you think of that eat seeds or fruit?"
Students work on their diagram I give them a 'heads-up' when there is about 10 mins. left to finish before we have our wrap-up.
To get students moving and talking about their work, students conduct a 'gallery walk. Students leave their seed dispersal diagrams displayed neatly on their desks and walk around the room to see how others conveyed information on their diagrams.
I am one of the gallery walkers too, noting to student viewers what I see that was well done, or asking questions.
After 5 mins., I ask students to turn in their 'seed dispersal diagrams' if finished, if not they will place their work in their folder to work on later in the week. When I look over the work, I am looking that they labeled parts of the seed that would help it with that type of seed dispersal. (embed student work)
Next time, I will prompt students to review their diagrams to see if there is anything they want to add and/or change on their diagrams based on what they saw on their gallery walk and the criteria we have for what should be on a diagram. This will help students develop independence in their learning, checking their work with criteria each other.
After work has been put away, botanists come to the rug. We look at our plant log and I ask students what new information could we add, any information to be revised, or new questions to include. After the log is updated, students are dismissed.
"Botanists we learned that many seeds move away from the parent plant so that they may have a better chance of getting sunlight, water and nutrients. If we look closely at a seed could you make a hypothesis about how it travels?"
Later this week and before the next lesson, I will integrate the concept of seed dispersal into other parts of the students' day, to reinforce the science concepts students have worked with this week.
When I review students diagrams I will be checking that students have included diagram parts and that the diagram conveys understanding of the seed attributes that help with that dispersal method.
Labeled Parts: seed, lift element (could be labeled as fluff or fuzz, blade)
Convey Understanding: may have arrows to show how seed is lifted into the air or blade spins, may include many seeds in the drawing
Labeled Parts: seed, plant
Convey Understanding: arrows or seeds moving out from the plant, words to describe how plant sends seeds out, i.e. explodes
Labeled Parts: seed, seed coat
Convey Understanding: seed in the water
Labeled Parts: seed, hook or spike,
Convey Understanding: seed on animal, or animal eating seed