Lesson 5 of 6
Objective: Students learn that pinecones can close up to protect seeds by observing what happens when placing open pinecones in water.
Students are asked to sit at their seats in order to do an experiment with pinecones.
Since we briefly discussed pine cones in the previous lesson, students are aware that evergreen trees bear cones. I reference this again to remind them.
I say, “We live in a Ponderosa Pine forest and we have a lot of pine cones around. How many of you have seen a pine cone before?”
I ask this question to get a good understanding of who has the prior knowledge and who might not.
I explain to students again, that evergreen trees do not grow flowers or produce fruit like deciduous trees do. So, their seeds come from the pine cone.
Guided Practice - Experiment
On each table, there is a large pile of various types and kinds of pinecones. I make sure to include open pinecones and closed pinecones.
I ask students to first sort the pinecones by “open” and “closed”. I give them a few minutes to do this and then I ask the students to talk to their table group about why they think some are open and some are closed.
I give students a few minutes to talk about this and then I go on to ask, “Did you know that the seed lie inside of the pincone? Does that change your thinking of why a pinecone is open or closed?”
I wait for responses.
I go on to explain to students that the seeds inside of a pinecone are typically spread by the wind and that the pinecone must be opened up for the wind to catch the seeds and blow them away. At this time, I will pull out some evergreen seeds to show the class how lightweight they are. I also show them where on the pinecone the seeds are.
Next, I pose a question to the class.
“How do you think a pinecone protects the from rain and moisture?”
I record the responses on the board.
I then explain the experiment. Since we cannot make it rain inside the classroom, we are going to soak pinecones in a tub of water to see what may or may not happen to them.
I ask the students to find the best pinecone in their pile of “open” pinecones and place it the tub of water.
I ask the students to turn to their table partner and talk about their prediction of what will happen to the pinecone.
I explain to students that we will move on to other work for awhile and come back to check on our experiment after awhile.
In about an hour, I ask the students to come back to the table and take a look at their pinecone. What should happen is that the pinecone will now be closed up. This usually gets the students excited because they weren’t really expecting it.
I ask, “Why do you think this happened? Turn to you table partner and discuss it.”
To close this lesson/experiment, I bring the students back to the meeting place rug to continue teaching them that pine cones can adapt to their surroundings in order to protect the seeds.
I ask students, "Why do you think that the pine cone closed up while it was in the water?"
I record answers on the white board. The majority of the students will be able to say that it is to protect the seeds.
I continue to explain, "the seeds are meant to be spread by wind so when there is an abundance of moisture, the cone will close up to protect the seeds."