By Kevin Le Serre, Biology Teacher at RBIS International School
Biology, the study of life, is a captivating and dynamic field that constantly evolves with new discoveries and technological advancements. As a Biology teacher, my primary goal is to instill a deep understanding of biological concepts in my students. To achieve this, I employ various teaching methods, one of the most crucial being the use of models and representations. Scientific models are simplified representations of complex systems, serving as tools that enable scientists to better organize and structure the knowledge they gather. They can be physical, visual, computational, or any other way that a thought can be represented. Visual models include graphs, diagrams, and animations whereas physical models are typically made from solid material.
In a 2016 publication 1, Caleb M. Bryce and the other authors highlight that models serve as a starting point for investigation and possess not just illustrative but explanatory capabilities. This article is intended to provide insights into how I use various physical models, with the goal of enhancing the educational experience in my Biology classes at RBIS International School.
In a recent biology lesson with my Year 8 students, we delved into the fascinating world of respiration and the respiratory system. After learning about the pathways through which air travels, from the trachea to the bronchi, bronchioles, and alveoli, we posed a crucial question: "What makes this air move?"
To explore this question, I introduced a hands-on activity where students had to build a model lung to illustrate how lung ventilation works. This project utilized simple, readily available materials, such as plastic bottles, balloons, and straws.
To witness the model lung in action, the students participated in a dynamic experiment.
They started by manipulating the 'diaphragm' represented by a cut balloon, which they pulled down and then allowed to naturally return to its original position. This interactive process served as a visual representation of the 'diaphragm' pivotal role in our respiratory system. As the diaphragm descended, mimicking inhalation, the 'lungs'—illustrated by red balloons—swelled and expanded, beautifully simulating the inhalation process. When the diaphragm returned to its resting position, it demonstrated the exhalation phase, causing the 'lungs' to deflate.
This hands-on activity made lung ventilation easier to understand and helped the students better appreciate the complexities of the respiratory system. Additionally, it provided an excellent opportunity for them to develop their critical thinking skills as they assessed the model's limitations. They observed that while the model effectively illustrated lung inflation and deflation, it did not perfectly represent the intricacies of the human respiratory system. For instance, the single balloon used to simulate both lungs served as a simplification, whereas humans have two separate lungs.
This example illustrates how we can encourage our students to Think and Work Scientifically, an essential skill in the Cambridge Science curriculum 2.
In a recent biology class for Year 11 students, we explored the complex topic of digestion.
To give more interactivity and depth to the learning process, I introduced an activity involving human torso models. The students were organized into groups, with each group tasked with the challenge of using a human torso model to not only identify and label the various digestive system organs but also to prepare an oral presentation explaining their functions and interactions. The highlight of this exercise was the 5-minute group presentations in front of their peers.
Using human torso models not only brings the subject matter to life but also deepens the students, comprehension, and memory retention. Through active engagement with the models and the need to articulate their knowledge to fellow students, the learners can solidify their own understanding while benefiting from the collective wisdom of their peers.
This peer learning environment encourages the acquisition of new insights and perspectives, fostering critical thinking, communication abilities, and teamwork.
For young learners, I believe that using physical models is particularly important.
In one of my Year 7 Biology lessons this school year, we explored the world of cells, a fundamental topic in the curriculum at RBIS. To make the learning process exciting and hands-on, I challenged the students to create 3D cell models.
At the start, the students had to choose whether they wanted to build a plant cell or an animal cell. Then, they made a list of all the parts they needed to include in their 3D cell models. This step was important because it helped them see how each part has a unique job and look.
The students put a lot of effort into creating their 3D cell models, and they did a fantastic job. This practical approach not only made learning about cells more enjoyable but also greatly improved the students, understanding of how cells are structured and how they function.
Moreover, this activity also cultivates a range of specific skills that are highly valuable in scientific careers. In 2019 article 3, Juan Cristobal Castro-Alonso and David H. Uttal emphasized the need for visuospatial skills in health and natural science professions. This suggests that when students learn using visuospatial methods, they not only acquire course content but also enhance their visuospatial skills simultaneously.
In the context of learning about biological molecules in IGCSE Biology 4, It's essential to underscore the importance of physical models.
For example, I frequently encourage my students to create models of biological molecules using modeling clay. This hands-on approach provides a unique opportunity for them to explore the intricate spatial configurations of key organic molecules, including DNA, proteins, carbohydrates, and lipids. They sculpt and assemble these models, allowing them to visualize the structural nuances of each molecule, such as the double helix of DNA or the folded globular shape of proteins.
This engagement not only helps students to comprehend the molecular shapes but also deepens their understanding of the link between structure and function. They gain insights into how DNA stores genetic information, how proteins catalyze chemical reactions, how carbohydrates serve as energy sources, and how lipids are essential components of cell membranes. I believe these hands-on activities make the subject both accessible and fascinating for our IGCSE Biology learners.
Conclusion In the world of Biology, models are crucial tools for teaching and learning. They play a vital role in my biology lessons, serving as essential aids for effective teaching and learning. They possess the remarkable ability to simplify intricate biological concepts, thus rendering them more accessible and captivating for my students. Physical models, which are like hands-on models you can touch and play with, are especially effective. They let students dive into biology and explore things in a fun and interactive way. These experiences are pivotal in nurturing the next generation of scientists, researchers, and environmentally conscious individuals, all driven by a deep-seated love for science.
References:
1 Bryce et al. Exploring Models in the Biology Classroom. Article in The American Biology Teacher · December 2015
2 Cambridge University Press & Assessment - Emma McCrea (2021). What is Thinking and Working Scientifically? https://www.cambridge.org/us/education/blog/2021/11/05/what-is-thinking-and-working-scientifically/
3 Juan Cristobal Castro-Alonso, David H. Uttal. Science Education and Visuospatial Processing. August 2019 https://www.researchgate.net/publication/334968946_Science_Education_and_Visuospatial_Processing
