Our human practices program "Education" aimed to reach students of different age groups. So we decided to introduce topics from the field of synthetic biology to elementary school kids and get them excited about biology.
As a topic, we agreed in the group on the introduction of DNA as the code for the building plan of living things. To design the lessons, we asked the mother of one of our team members, who is working as a teacher in an elementary school, for feedback on our lesson plan. She gave us some helpful advice to incorporate into our lesson plan. For example, she told us that children understand new factual content better when it builds on what they already know. So she advised us to introduce DNA as a secret code since this topic had already been covered in class. She also gave us the idea of explaining the triplet code using peg cubes since these were already familiar from their math class and would help visualize the topic. She also pointed out that a feedback session at the end of the lesson was important because the children need to reflect on what they learned in class and what interested them. Based on this feedback, we developed a lesson plan and delivered a lesson in one third and fourth-grade class.
During the lesson, we first introduced the concept of DNA as a secret code that encodes a building plan for the human body. Then, using a worksheet we designed ourselves, we explained the principle of the triplet code of DNA as follows:
There are plug-in cubes in four different colors: red, blue, green, and yellow. Three cubes together form a letter. The colors can be linked arbitrarily, meaning that there does not always have to be three different colors. The important thing is
the order of the chain of cubes, which one always reads from left to right.
The worksheets can be found here.
To illustrate this, we used cubes to make three triplet codes and had the students guess which letter each code would result in.
Afterward, the class had to work in groups on an exercise sheet on which the body characteristics of a person, such as eye and hair color, were coded using the triplet code. They then had to present their findings to the class. Finally, each child was allowed to code their own words or phrases and have them decoded by other children. In the process, some students quickly realized that not all letters of the alphabet or umlauts could be encoded with the number of triplet codes on the worksheet. As a result, they invented new triplet codes or supplemented them with information on how to read the code. We were particularly impressed by this, as it meant that the class automatically realized by themselves that other results would have the need for a concept of modifying the reading of the genetic code which could be compared to methylation in the biological world.
In the last part of the lesson, we had the students think about where this secret code might be "hidden" in our bodies. Here, it was already known to some students from the third and fourth grades that cells are the smallest building blocks of our body. To illustrate how a living being is made up of many small cells, we again used peg cubes. We introduced the cell nucleus as a kind of "safe" in which the DNA is securely packed so that it cannot be accessed and read arbitrarily from the outside. Finally, we wanted to show the students what a cell and its nucleus actually look like in reality. To do this, we prepared the skin of red onion on a microscope slide, which the children were then allowed to take a look at under the microscope. Afterward, the class discussed on the blackboard what the cells and the cell nucleus looked like in case not all children could determine their structure under the microscope.
At the end of the lesson, we conducted an oral feedback session with the two classes. In doing so, we asked the students what they enjoyed, what they learned, where difficulties occurred, and what they would still be interested in learning. The feedback session showed that almost every student enjoyed microscopy the most. Many students were particularly fascinated by the structure of the onion cell and the fact that plant cells also have DNA. The second most popular lesson activity was decoding the secret code and inventing their own code words and phrases. One difficulty that stood out in the feedback was that third-grade students in particular, had trouble understanding exactly where cells are located in the human body. For them, the concept of the body being made up of many cells was still too abstract. Also, at the end of the lesson in the fourth grade, we received feedback from the class teacher present, who rated the lesson as very positive overall. In her opinion, the idea of having students encode their own words or sentences was very good. Also, the secret code explained the function of DNA well. She also found the comparison of the large cube with cells (many cells build up bodies, as many small cubes build up the large cube) to be very vivid for the children.