New Zealand Science Teacher

Living world in yrs 11-13

15/01/2012

by Kate Rice, President of BEANZ

My dog was diagnosed with a heart murmur by the vet who described what this meant and then prescribed medication to help the ‘heart work better’. The vet’s explanation for the dog’s coughing was: “The valve in the left of the heart is letting fluid run back into the lungs. The dog coughs to get rid of this fluid from the lungs.”

As a biology teacher I reflected on the explanation and the image it produced for me. From this, I visualised fluid (blood) building up in the lungs as blood is pumped round the body by the heart. But how would the blood get into the lungs as it is retained in capillaries? Is my dog really coughing up fluid, or using coughing to assist the movement of blood in the lung capillaries back towards the heart?

We teach our students that lungs are not muscular, but bags suspended in the chest cavity, with intercostal muscles and diaphragm contracting to assist gas exchange. Was the vet giving an explanation adequate for people to understand the affliction without completely stating the science behind the process? Is the vet’s explanation good enough for most people? (Scanlon, Murphy, Thomas, & Whitelegg, 2004)

This made me reflect on the biology we teach, the texts students use and the focus placed on ‘Living World’ achievement objectives. Would building more Nature of Science (NoS) into teaching and learning programmes help students better understand socio-scientific issues in their world? Find out about health issues they or their parents are likely to come up against? Could programmes allow time to find out about causes, effects and treatments for: bypass surgery; heart murmurs; asthma; and blocked arteries?

Upon hearing the dog’s ailment, my physiotherapist daughter responded “I didn’t think of dogs having heart murmurs. It’s what happens in humans with faulty heart valves. I hadn’t thought of them being like us!” Back to the textbooks for some comparative anatomy, all of which raises questions about how we teach circulation and gas exchange. Do we focus on ‘humans’? Will a human biology focus increase student engagement? Do we bring NoS aspects into teaching and learning programmes?

By using models and investigating relationships between scientific theories and the models, can we help students build a better understanding of the relationships between structure and function in living organisms? For example, many texts use stylised heart structure and double circulation systems’ diagrams. As teachers, we know you cannot find this when dissecting a mammal, but many students don’t link dissection findings to theoretical diagrams in textbooks. Clarifying and explaining the use of models and generalisations are essential parts of NoS in teaching. and address both ‘understanding about science’ and ‘investigating in science’ within the NoS strand on the New Zealand Curriculum (Ministry of Education, 2007).

Building NoS into Year 11–13 programmes will address student questions about their own ‘Living World’. Accumulate students’ questions as each topic progresses. Allow time to address these as the topic unfolds. Teachers do not have to provide all the answers; use the NoS aspects to help students find different ways to seek information and provide responses. Some of their search for suitable information for responses can provide valid assessment opportunities using internal standards such as Biology 1.2, 2.2, 2.3 or 3.2 too!

Engage students better with their own ‘Living World’.