Using Beads to Turn Lightbulbs on

Abstract ideas are often hard to grasp.

That’s why UAHS honors biology teacher, Tim Bridgham, gave his students a bag of beads.

I noticed him compiling them in the library and I couldn’t resist the urge to inquire. When he gave me his answer, I asked if I could drop in for a visit.

The following morning, I watched as Bridgham helped his students make sense of linked genes and how their locations on a particular chromosome affect inheritance patterns.

As I sat in the back of the room, I found my mind trailing back to the seemingly endless number of Punnett charts I drew by hand, matching variations of X, x, Y and y. And if I’m being honest, despite figuring out how to successfully write and predict the patterns for tests, I don’t think I ever got to a place where I could visualize what they meant.

After watching Bridgham’s students manipulate beads and discuss what those manipulations meant, I’m quite sure their sense of linked genes and inheritance patterns is a whole lot deeper than mine ever was.

Bridgham started out by warning that they “will probably get frustrated,” but he encouraged them, and challenged them, to read carefully. “Hopefully,” he said, “the light bulbs will start to go on.”

Then he gave them the chance to pick partners, grab a baggie and get started.

“Our expectation is that by 10:10 we will be somewhere on page 2,” he told them. “We will not be collecting numbers until tomorrow. Our first big step is to understand why [patterns] exist.”

Pairs worked at their own pace, some moving quite slowly, challenging one another at every bend in the process; others seemed to fly through, making their way past the setup, and into the part where they would collect data.

When one of the groups struggled to remember what a centromere was, her partner knew exactly where to go to pull up past resources, and together, they revisited previous learning. When a student forgot how to determine which letter was dominant and which was recessive, his partner clarified.

I saw them work through three or four different challenges without raising their hands, without asking Mr. Bridgham to save them from the hard work.

And when they did need his assistance, Mr. Bridgham used the beads to help them see the answer. He had them turn their strands until they accomplished the right orientation.

Then he directed them back to the question: “Build a homologous chromosome…[then] build a matching chromosome (one inherited from the other parent) using the following: 6 red, 1 green, 20 red, 1 white...after meiosis occurs, what would be the possible gametes (assume NO crossing over YET)?”

At first they said there were four combinations, but Mr. Bridgham challenged them to look at the options again, “remember, there’s no crossing over,” he told them uncrossing their crossed beads.

Then the students looked down and actually examined what was in front of them. Right way, they saw that the answer was two instead of four.

The light bulbs Bridgham mentioned at the start of class?

I could actually see them going on.

While some people are able to read words and visualize concepts without actually touching them, or seeing them, for many others, abstraction can be a guessing game or a simple game of process memorization.

At least it was for me.

So when teachers take the time to create experiences like Bridgham did, one that makes these concepts tangible, they give their students a gift.

They give them the opportunity to move from understanding a process they might eventually forget, to understanding the significance of an idea and how that idea transfers to other situations.

They give them the chance to go beyond the mechanics and understand the reasons, so they can be better equipped to solve other problems or to imagine other solutions.

They give them a reason to remember what they learn, and consequently, it makes what they learn much harder to forget.