Teaching microscopy using plants; build confidence, prepare slides, measure and calibrate

This session will showcase the work done by SAPS on using plants in microscopy teaching to help build teacher, technician and student confidence in using microscopes, preparing slides and measuring specimens effectively. This workshop is for anyone wanting to become confident in teaching microscopy to secondary students of any age. We will explore some critical concepts in microscopy, slide preparation, and calibration and measuring, and suggest interesting specimens to use for these areas which also allow for student investigations. We will look at a dandelion seed’s filamentous parachute-like structure (its pappus) to explore how mental models of the 3D structure of objects can be built up from the 2D optical slices seen under a microscope. This will be extended to looking at the leaves of the pondweed Egeria densa, where chloroplasts can be seen zooming around cells. We will see how studying the leaves of Tradescantia zebrina can help students maintain a sense of scale when progressing from the ‘just visible with the naked eye’ to ‘only visible with a microscope’. To focus on slide preparation we will look at red pepper (Capsicum annuum), banana (Solanum tuberosum) smears, pear (Pyrus spp.) scrapes and apple (Malus sp.) pulp as examples to use for investigations. These easy to prepare specimens provide the opportunity for students to develop their skills and understanding about slide preparation while answering questions such as ‘What makes the skin of a red bell pepper red?’, ‘What changes occur in the cells of a banana as it ripens?’ and ‘Why do pears have a coarse texture?’ We will also explore calibration and measuring activities investigating cell size and growth in red onion (Allium cepa), stomatal density in Tradescantia zebrina and the speed of chloroplast movement in the pondweed Egeria densa. These approaches will help you teach microscopy lessons that help students become confident and enthusiastic users of microscopes and skilled interpreters of what they see. Participants will: •Build confidence in how a microscope works to help troubleshoot students’ problems quickly. •Find out about specimens that allow students to make progress with microscopy more independently. •Explore two of the most fundamental components of slide preparation •Develop knowledge for teaching calibration and measuring skills, including preparatory activities to support students. •Find out about specimens that demonstrate these components and provide the opportunity to carry out investigations Participants’ students will: •Gain a better appreciation of why microscopes need to be operated in a particular way making them more likely to follow the required steps and so more likely to have success with a microscope. •Develop a deeper understanding of critical concepts in microscopy, helping them become confident users of microscopes and skilled interpreters of what they see, able to independently carry out investigations.