During the 13th and 14th of Jan 2016, I demonstrated in two practical (laboratory) classes for a first year biology unit, Cells and Genes. We were working through some examples of ‘Patterns of Inheritance’ which can be tricky stuff when first being introduced to the ideas. I was feeling pretty comfortable with my ability to teach the prac because I had done it several times over the last few years. However, there were a few differences that helped me learn some valuable lessons.
The most important lesson was that for effective learning to occur ‘both teacher and students need to be prepared for the lesson’.
For me (the teacher), I was filling in for friend who was away and because I had taken the prac before I thought it would be a walk in the park. It wasn’t! I didn’t receive the prac notes, or questions that the students needed to answer, until a couple of hours before the class started, and never got a version with the answers. While not having an answer sheet wasn’t a major problem for the questions based on theory, the prac required students to count flies and record their traits so that they could look at inheritance patterns over three generations. The numbers that they got in the first and second generations impacted all following questions so they needed to be pretty accurate. The problem was that it recording the correct fly traits was difficult.
After my first prac I recognised that a large amount of the difficulty students were having with the prac was becuase they lacked some fundamental knowledge about the science we were doing. This included knowing the following:
- What chromosomes, genes and alleles are and what happens during meiosis.
- Terminology such as genotype and phenotype.
Many of the students also seemed to have real difficulty making the conceptual link between a representation of biology, e.g. Rr, actually means biologically, e.g. Dominant Purple Allele-Recessive Yellow Allele. Some students found it very hard to understand that this was a representation of an individuals alleles and allowed you to predict what colour they would be.
Some students also seemed to lack the confidence to attempt an answer even if they knew what the answer was.
I found that after my first session I wanted to try and address a few of these issue, so during the second prac I tried to introduce the concept of chromosomes, genes and alleles and how they relate to each other. I also tried to relate the parents of a punnet square to the actual individuals that we were theoretically breeding.
I also recognised that students needed to want to engage with what we were discussing rather than simply going through the motions and waiting to be given an answer. Those students who were really engaging with what we were doing grasped the concepts better than those that were disengaged.
If I ever taught this topic again in the same setting I would probably look at including more of an introduction about the fundamental ideas behind inheritance, and make the ‘breeding’ more explicitly between individuals rather than the concept of individuals.
In future practical and tutorial classes I will begin by trying to establishing an understanding of students incoming knowledge and try to work from where the student is beginning.