Lab 1 Microscope North Seattle Comunity College1显微镜实验室北西雅图社区学院.docVIP

Experimental Design and Investigating Diffusion and Osmosis Objectives: To practice applying hypothesis testing. To further your understanding of experimental design. To gain a better understanding of diffusion and osmosis. To understand these terms: diffusion, osmosis, diffusion or concentration gradient, Brownian movement (or motion), hyposmotic, hyperosmotic, isosmotic, hypotonic, hypertonic, isotonic, hypothesis, selectively permeable, semipermeable, prediction, control, independent variable, dependent variable. Introduction This lab will introduce you to 1) diffusion and osmosis (especially as they relate cell membranes) and 2) the scientific method. You will actually be using the scientific method as you work through one of the activities (the “egg” lab) in this lab. In this introduction, we will focus on the scientific method as you should have already discussed in detail the concepts of diffusion and osmosis as they relate to the living cell (and its membranes). If you have questions about the “science” of diffusion and osmosis please consult your textbook and/or your instructor. The scientific method is basically a fairly rigid way of thinking allowing scientists to systematically approach a problem or interesting observation. This method is based in part on establishing hypotheses and predictions, leading to setting up an “experiment”, and then analyzing the experimental results and drawing conclusions about how these results either support or refute the initial hypothesis and predictions. The scientific method can be broken into several “steps”, and depending on the author, the method may involve 3, 4, 5, 6, 0r 7 steps. Regardless of the number of “steps”, however, the concept of this way of thinking is the same. For our intents and purposes, the scientific method will be broken down into 5 steps as follows: 1) Observation and Questioning, 2) Hypothesis, 3) Predictions, 4) Experiment, and 5) Analysis and Conclusions. Brief descriptions of thes