Lesson 2: Seed Germination (45 minutes: This should take place 1-2 weeks after Lesson 1)
With follow-up observations for 3-5 days and 45 minutes on the final day.
*This lesson will just focus on the seed going through the germination process
Key Question
- How does a seed germinate?
Learning Objectives
- The children will plan and conduct an investigation to determine the best germination conditions for corn seeds.
- The children will observe and record data (drawings and descriptions) while seeds are germinating.
- The children will analyze their recorded data, labeling structures they observe and indicating the functions for them.
Materials
- Corn seeds in 2 plastic bags *prepare before the lessons…. See Day 1 step 1
- Additional dry seeds
- Bags
- Water and a variety of other liquids such as orange juice, soda, energy drink, vinegar, oil, milk, baking soda water mixture
- Science notebook with seed growth journals (page S7)
- Colored pencils
- Magnifying glass
- Corn seed germination diagram with labeled structures (page S2-4)
Before the Lesson
- Set up two bags 3 days prior to the lesson.
- Bag 1: just a corn kernel
- Bag 2: Corn kernel with some water in it.
- By day 3 the kernel with water should be germinating
Guided Teaching
Procedures for Instruction
DAY 1: (45 minutes)
1. Introduce the topic and assess prior understandings:
- Present the 2 bags of seeds to the children, one that had a little water and a seed in it and one that just had a seed in it.
- Tell the learner you aren’t sure what happened to the seeds: “Look what I found! Here are 2 bags of seeds.”
- Don’t tell students that one has water in it- let them discover this on their own. Pass the bags around.
- “What do you see?”
- “What do you think happened?”
- “They look different- I wonder why?”
2. Record the children’s thinking in their science journals and discuss as a group to assess their thinking. Do not signal right or wrong answers. Just let them discuss their ideas and guide the flow with such prompts as:
- “Can you say more about that?”
- “Why do you think that?”
- “Who agrees/disagrees with this idea and why?”
- “Does anyone have a different idea?”
- “Would this be true all the time?”
3. Develop an investigation based on the questions, “How does a seed germinate?” Hand out corn seeds and bags, letting children figure out that they will be placing a few seeds in each bag and seeing if they will germinate in different conditions. Have a variety of liquids setting out. Guide the development of the investigation with such questions as:
- “What does a seed need to germinate?” (Based on the introductory activity, they should realize it needs water. If not, guide them to reflect on the introductory activity to understand this.)
- “Does it have to be water or can it be any liquid? Does it have to be a liquid?”
- “Which liquid will work best? Why?”
- “Should the bag be opened or closed? Why?”
4. Focus the elements of their investigations:
- “What are our research question or questions?” Have the children generate their own questions about the seeds.
- “What kind of data do we need to collect to show what we know?” (Introduce seed germination journal pages and how they will observe, draw and write in their science journals.)
- “What are the different conditions (variables) you want to test?” Let the children pick the different kinds of liquids they would like to test.
- “Should we have something to compare to? Would the seeds just have germinated anyway? Should we set up comparisons of bags (control group) using no water and just water?”
- “What do you think will happen and why in each condition?” Have them record this as a prediction or hypothesis.
DAYS 2-5:
1. Record the children’s observations in their journals by drawing and writing. Use colored pencils and magnifying glasses.
- Each day for 3-5 days, have children observe the progress of the germinating seeds and record their data. Be sure the learner draws and writes in their journals what they see happening with the corn seeds in their bags.
FINAL DAY (45 Minutes)
1. Discuss the children’s findings by sharing results. Lead the discussion with such questions as:
- “The corn seeds germinated best in which conditions?”
- “How did the various liquids compare to the control conditions (water and dry)?”
- “Why do you think you got the results you did?”
- “Were there any contradictory results?”
- “What new questions do you have based on your findings?”
- “Based on your evidence, how do you think a corn seed germinates?”
- “Do you think this is true of all seeds? How could we find out?”
2. Explore seed and sprouting seed structures by asking children to examine their drawings from the different days.
- Have them label the different structures they drew or wrote about. Do not give them the “proper” terms for the structures. Let them use their own descriptive words.
- Then have them suggest functions for each structure. Again, do not signal if they are correct or not, but have them justify why they think that. Encourage their thinking.
- Discuss these structures and have the learner share their labeled structures and proposed functions.
3.Explain how their discoveries are very much like those of scientists’ discoveries.
- “You planned and conducted an investigation to determine how corn seeds germinate and you formed conclusions based on very convincing evidence! You are a budding scientist!”
- “You observed carefully and identified parts of the seeds and proposed functions for them. You are certainly budding scientists, because that’s what many plant scientists do, they observe carefully and identify structures on plants that many people never even knew were there! If those structures have no names, they have to name them. They also observe very carefully over time to see what functions those structures have.”
- “Let’s look at what scientists have named the structures you identified and what they have found are their functions.”
4.Show a diagram (model) of corn seed germination, with major structures labeled.
- Distribute copies of diagrams to the children and have them label the structures as you guide them.
- Have them compare their terms for each structure to the term scientists use.
- If they have room, they can label their own drawings with scientific terms.
- Discuss the function of each structure.
5. Conclude:
- “Were you surprised to discover so much going on in the seed as you observed them germinating?”
- “What do you wonder about now?”
- Show the time lapse videos of corn growth
Early Elementary Activity
Science
- The outside layer of the corn seed is called the seed coat. What is the job of the seed coat? Do other seeds have seed coats? Think about sunflower seeds, apple seeds, watermelon seeds, etc. Do some research to find out more about the job of a seed coat.
Art/English Language Arts
- An idiom is a phrase that has a figurative meaning that is different from the literal meaning.
- Example: It is raining cats and dogs has the figurative meaning of raining very hard – the literal meaning would be cats and dogs falling from the sky! If you were to draw a picture of the literal meaning, it would be a picture of cats and dogs falling from the sky.
- Think about the seed coat you just learned more about. Draw a picture to show the literal meaning of seed coat. So draw your corn seed in a coat. Be creative! Is it in a winter coat, a raincoat, or maybe a coat that makes it look like a dinosaur!
Upper Elementary Activity
Science
- Dig deeper. Below is more information about the corn seed. Use the diagram on page S3 as you go through this extra information. Encourage further research about seed germination by looking online. Either watching videos or comparing the corn seed to a sunflower seed. Do all seeds have coleoptile, radicle and hypocotyl?
Extra Information for the Educator
A seed is the house for a future plant, outfitted to furnish what a baby plant needs to start to grow and succeed in life. A seed is wrapped in a tough outer coating (seed coat) that prevents the future plant from damage. Inside, there is a food supply and the beginnings of a new plant. In the world of flowering plants, there are monocots and dicots. A monocot seed has an embryo that contains one cotyledon, the part of the plant that becomes its first leaf-like structures. A dicot seed has an embryo with two cotyledons. The cotyledons help provide and absorb nutrients from the plant until the plant is ready to make its own food through photosynthesis. Corn kernels are monocots and beans are dicots.
Inside a corn kernel (seed) there is a cotyledon near the bottom, pointy part of the kernel, where the new plant begins to grow. It is surrounded by the endosperm, which is starchy food for the baby plant. When the seed begins to grow, its protective covering breaks open in two places. The top breaks open to reveal the coleoptile and eventually the plumule, the future shoot of the plant. The bottom breaks open to reveal the coleorhiza and eventually the radicle, the future root of the plant.
Like the corn seed, the bean seed has places where the root and the leaves emerge. However, since bean seeds are dicots, when you open one up, you’ll see it has two cotyledons that look like reverse copies of each other. Instead of having a separate baby plant and food supply, inside the bean plant the cotyledons contain the endosperm (the food supply).
As the root grows, tiny little root hairs extend out to form a net-like mass to absorb water at a microscopic level. Guide the children to look for these and all the structures using magnifying lenses.