Looking Through A Microscope
Lesson 8 of 9
Objective: SWBAT prepare a wet mount slide to identify microorganisms in pond water.
How to prepare a wet mount slide
A visual demonstration is best practice. It gives students an idea of the process and procedure and models the behavior you need to see in the lesson.
As students watch the video, I ask them to put in order the Steps to Prepare A Wet Mount Slide.
After the video, give students 1 minute to talk with their partner and check their work. Then, share the correct answers as a class and have students check their work. Chronology is important because the exact order in which events occur helps students to understand the cause and effect of those events. Cause and effect (#2 Cross Cutting Concept) is an important concept because it guides student thinking and explains causal relationships.
Microscopes & Microorganisms
Draw what you saw. Microscopes & Microorganisms.
This strategy (draw what you saw) gives students an opportunity to process what they saw. I ask students to use their Science Journal to record what they saw. On the board (Smart Board, White Board, Chalk Board) I post the following:
1. Make a wet mount slide using the pond water.
2. Draw what you saw at three (3) different power magnifications. Use colored pencils to show details.
3. Label each drawing with the power magnification.
As students view their slide with specimens from the pond, I want them to make connections about the biodiversity of pond life. Students are acting like a microbiologist, just as Anton van Leeuwenhoek did in the 1600's. Evidence of biodiversity will be important data for later in this problem-based learning experience where students collect data/evidence, compose an argument, and then answer the essential question "What are the benefits of parks in a community?"
To extend this microscope activity, have students take their drawings and use them to identify creatures on their own using the website Nikon Microscopy. This website has images of a variety of microorganisms that students would find in North America. To increase the rigor, have students compare their findings with other students in class. Students will be exposed to looking at other's work and comparing it with their own to see if they have made a match.
Optional: Try using this microscope which fits over the camera on your smartphone or tablet called Prank Star Microscope. It is a 30x device that produces a great, powerful image!
Wrap It Up
Explain what happens to our view of an image as you increase the power of magnification.
I give students one minute to (Think Pair Share) process the question and write a response in their Science Journal. Then I ask students to turn and talk with their partner, for one minute, about their response. Finally, we share out as a class. I am looking for answers such as: the image gets bigger, I can see more details on the image, the image looks closer.