Teaching Biology using Student-directed Portfolios
I’ve had an overwhelming positive response from my students towards student-directed portfolios. The portfolios provide students with choice, differentiated worksheets and allow students to work at their own pace. A star system is used where students need to obtain at least 15 stars to complete their portfolio. Our faculty is currently implementing student-directed portfolios for Years 7-10.
Recently, the Year 10 students had three to four weeks to work on their “Code of Life” portfolios. For the first couple of lessons students were front-loaded with the terminology and core concepts of the unit in teacher-centred lessons. In this Biology unit, students were introduced to words such as “gene”, “genotype”, “phenotype”, “DNA” as well as concepts such as “DNA replication”, “mutation”, “punnet squares” and “pedigrees”. I found that explicitly teaching the core ideas of the unit to the students critical to the success of the next couple weeks as it enabled students to have the necessary prerequisite knowledge to work independently.
As part of the teacher-led introduction of the unit, students conducted an experiment to extract the DNA from a kiwi fruit. The students used a mortar and pestle to mash the kiwi up, taking care to break the seeds into a powder. They filtered the kiwi fruit to obtain the filtrate and added a mixture of citric acid, detergent and salt to break open the cell membranes. Alcohol was added to allow the DNA to collect at the top as jelly-like mass. There were many steps and only a few groups successfully extracted the DNA. The experiment was especially engaging for students as they had the opportunity to use a lot of equipment and work in teams.
From then on, students worked independently on a variety of activities. The activities include: graphing data, creating models, watching videos and reading articles to answer comprehension questions, conducting experiments to model inheritance, poster creation (using Canva), essay writing etc. There were worksheets for each activity and the worksheets were worth 1-3 stars each and were of varying difficulty. The activities themselves accounted for students preferred learning styles e.g. auditory, kinaesthetic, visual etc.
I found that students enjoyed working at their own pace and worked quite efficiently. The teacher’s role was to mark and check off student’s progress each lesson. I found that I was able to give valuable feedback to students about their work and give more time and attention to students who required it.
At the end of the unit, students completed a final presentation. This could be a speech on a biotechnology of their choice (stem cells, IVF, cloning, genetically-modified foods or vaccines), a presentation on a 3D DNA model (providing advantages and disadvantages of model making) or a stop motion movie on DNA replication. Some students from other classes also performed songs (a great idea!). Overall, I was very impressed with the quality of work and I’m looking forward to implementing student-directed portfolios with my other classes.
