Since I started teaching Microbiology a few years ago, I have found a new appreciation for the amazing things you can see and do with a microscope....but it is a labor of love to teach students. The days of microscope labs usually have me getting my 10k steps for the day pretty quickly, as I move from kid to kid trying to help them troubleshoot their issues. However, it is absolutely worth it. Students are usually so engaged and intrigued by what they see and sparking their curiosity is easy.
Here's a lab I use in my 9th grade biology class.
Goals:
Students will earn how to use a microscope. They will be able to find objects on scanning, and then magnify them on low and high power.
Students will identify main structures of eukaryotic cells: nucleus, cell membrane, and cell wall.
Students will be able to identify the difference between a prokaryotic and eukaryotic cell.
Students will be able to identify the difference between a plant and animal cell.
This lab is broken up into two parts: basic microscope skills and identification of prokaryote, animal, and plant cells.
Part 1: Microscope Skills
- Students will walk through a series of questions that help them identify main parts of the microscope and their function.
- Students look at a print letter "e." This is an easy object to find, so it works well for the first one. Then students discuss what happens when you move from low to high power and how that effects the field of view.
- Next, students observe three fibers slide. They look at how you can only focus on one plane at a time and they determine what the order of the color threads are in on the slide.
Part 2: Prokaryote, Plant, and Animal Slides
- Students receive a generic animal, plant, and bacteria slides. They observe them on high and oil immersion power (bacteria).
- Students then draw and label all major parts of the cells. These slides are there "model" cells for the next part.
- When they have finished, they will obtain a "mystery slide." These are more difficult slides...often I choose tissue samples from plants and animals. The mystery slide has the slide name covered up, so they aren't sure of what slide they have. Here are examples of slides that I use.
- Students look at the slide and draw what they see. Then they have to decide what type of cell/s they are looking at: prokaryotic, animal, or plant.
- They will write a CER to answer the question: What type of cell is your mystery slide?
What do I look for in the CER?
Problem: What type of cell is on the mystery slide?
Claim: The mystery slide contains ____________. (prokaryote, animal, or plant)
Evidence:
- structures, number of cells, size as their evidence
- color is not evidence
Reasoning:
- contains a nucleus--- means it is a eukaryote
- cell wall or absence of cell wall
- organized (rectangular or square) or unorganized (no distinct shape)
Happy Teaching!
Mrs. Townsend