Unit Design:

• • Ideas of Growth. The overarching question is “how do things (complex organisms) grow?”. We start by observing pond water and discussing the characteristics of living things. Next, we focus on the growth characteristic of life and develop two hypotheses: (1) things grow because cells get bigger and (2) things grow because cells increase in number. Then we start looking for evidence!

  • Lots of Microscope Use. In building the unit, I wanted to put everything possible under the microscope, so we use this historically foundational instrument regularly. Our parent’s council donated money so we could buy smartphone mounts for the microscopes – this is a game changer for cooperative group work. Eventually we noticed strange things happening to the nuclei of onion root-tip cells.

  • Developing Our Model. This brings us to our study of mitosis and the cell cycle. Our model of the cell cycle starts very simply (process A and process B) and becomes more complex as we understand all the things that happen as a complex organism grows.

  • Biological Memory Work. We address an important pedagogical issue at this point. We explain why it is important to memorize a lot of biological terms and, more importantly, we teach students how to memorize things.

  • Observations before labels. After we examine our own cheek cells and a histological cheek tissue sample, we realize that our cell cycle model needs improving: not all cells look the same! We need to incorporate cellular differentiation into the cycle! This leads to our exploration of cell and tissue types, the next natural step as organisms grow.  As we do this, students are always looking at real things first, before we figure out what they do and then label them. This is how science works! For example, we look at electron microscope images and histology images of different cells types. This allows us to observe their form and ponder their function. The lesson presents this as a function-matching challenge for the different cell types. We take a similar approach as the organism complexity increases and we discover organ and organ systems.  We begin by examining histological cross-sections of the major digestive organs, again noting their form and sorting them into two categories (tubes and dense organs filled with gland cells).

  • Case Studies and Health Knowledge. For our exploration of organ systems, the last part of the biology unit, I take a new approach. With each lesson, students role-play a medical professional (community health nurse, family doctor, pulmonary surgeon, etc.) and a patient walks in! They present symptoms and we order tests. This motivates our further exploration of the organ systems with the goals of explaining the symptoms using their biology knowledge and providing a diagnosis. In each lesson, students are looking at real things: biopsy tissue samples, blood smear results, chest x-rays, endoscope images, and more. The goal of this approach is to move the learning experience away from presenting lists of parts and functions to providing experiences that prompt the need to learn more and provide opportunities to use their new-found knowledge to explain illnesses.  It occurred to me how important this approach was considering that the average student will only have this grade 10 experience to formally learn about organ systems to help them throughout the medical health experiences of their life.