Teaching roots and stems? To convey their structures and functions, try these ideas. First, try a quick experiment that compares plants with three types of roots – taproots, fibrous, and none at all. Second, use celery or a carnation to show how xylem pulls colored water up. Third, try a cool absorption activity.
Ms. Sneed Gathers Teaching Ideas for Roots and Stems
Once again, our favorite fourth grade teacher sat at the side table with her teaching partner. “On to the third part of our plant structures and functions unit,” she said. “First, we taught seeds, germination, and dispersal. Second, we dove into flowers and pollination. Now, we’ll plan stems and roots.”
“Aha,” Mr. Frank replied. “I liked the life science activities we did last year. Will we do them again?”
Ms. Sneed tapped her pencil on the table. Then she flipped open her laptop. “Yes. But I want to add one more thing.”
Preparing the Roots Lab
After a little clicking, Ms. Sneed found what she wanted. “Let’s prepare the roots lab first.”
Together, the two teachers studied the directions. Then Mr. Frank headed to the science cabinet. First, he pulled out a roll of paper towels and a stack of clear plastic cups. After placing them on the table, he grabbed a box of rice and some food coloring.
“I’ll get some tape and scissors from my desk,” said Ms. Sneed. “Then let’s try it out.”
Trying Out the Roots Lab
Once all the materials had been gathered, they set to work. Mr. Frank rolled three sheets of paper towel and taped each in the middle. After laying the first roll to the side, he cut the bottom of the second into strips. “So far,” he said to himself, “we have a plant with a taproot and another with fibrous roots.” Then he snipped off the bottom of the third roll. “And this poor plant has no root at all.”
In the meantime, Ms. Sneed had set out three clear plastic cups. She also poured water into a fourth cup and added a bit of food coloring. “Ready?”
“Yep.” Mr. Frank stuck the first two rolls into empty cups.
As soon as he was finished, his teaching partner poured rice over their bottoms. “Our first two are planted,” she said.
Finally, she poured rice into the third cup. Ceremoniously, Mr. Frank jammed the rootless plant onto the top.
“Now for the water.” Ms. Sneed poured some into the side of each cup. “Remember, we have to be careful not to get any directly on the paper towel.
Before too long, they had their initial results. While the colored water had traveled up the paper towels (or stems) that had “roots,” the third paper towel was dry.
“It’s apparent,” said Mr. Frank. “No roots, no transport of water.”
“Now for the final trial.” Ms. Sneed gave each roll a little push. The two with roots stayed upright, but the one with none fell over.”
“And no roots, no stability. Hopefully, our students will clearly see that plants need roots to take in water and anchor them in the ground.”
Soaking Celery Stems – A Tried and True Oldie
“On to the next lab,” said Ms. Sneed. “I did this in fourth grade. As a matter of fact, my mother probably did this in fourth grade. It’s an oldie but a goodie. We won’t need to try it out.” She pulled out the directions. All we’ll need are a cup, water, food coloring, and celery. Or we could use a carnation, which is pretty cool.”
“This year, I may try something fancier,” Mr. Frank said. “You know, cut the stem and put the two sides in different colors.”
Ms. Sneed chuckled. “A great variation on the theme. But what we really want kids to see is that water is absorbed by the tubes. More specifically, the xylem pull it upward.”
Another Stems and Roots Absorption Activity
The teacher pulled out yet another set of directions and grinned broadly. “Sure, this may be overkill. But I just love this absorption activity.”
As they looked it over, Mr. Frank made note of the materials needed: three clear plastic cups, water, blue and yellow food coloring, and two paper towels. “I love it too. So engaging. When the experiment begins, the cup on the left has yellow water and the cup on the right, blue. However, the middle cup has no water at all. Kids simply roll the paper towels. Then they place the ends of the first paper towel in the left-hand and middle cups. Similarly, they put the ends of the second paper towel in the right-hand and middle cups.”
“Last year, I did this at the end of the school day,” Ms. Sneed said. “The next morning, my kids were so surprised! Green water in the middle cup. Just another example of how xylem absorbs in stems and roots.”
Roots and Stems Have Xylem and Phloem
“What great activities!” Mr. Frank exclaimed. “But what did you want to add this year?”
“Well, I was thinking. Our students are definitely old enough to learn a little about xylem and phloem.”
She pulled up another page. “Over the weekend, I pulled together an introduction. And then I made a corresponding worksheet. Are you interested?”
“Of course! Whenever possible, I like to extend my kids’ knowledge.”
He took a closer look at the page. “Ahem. And maybe I can extend my own knowledge too. Sure, I remember the rolls of xylem and phloem in transporting materials. But I had no idea about their arrangements in monocots and dicots. This goes right along with our germination activities!”
“You know,” Mr. Frank added, “this is one of the best things about teaching. I get to keep learning about roots and stems – right along with my students!”
Ms. Sneed smiled. “Yep. Now on to leaves and photosynthesis!”