Cell Variety Lab

Whiteboard With your table partner write down the attributes of a scientific investigation. – (AKA what are the parts of a lab…)

Cell Variety Lab: Introduction/Background: The Cell Theory states that the cell is the basic structural, functional, and developmental unit of life. If this theory is correct, then all living things should be made up of cells. It should also be true that the cells of different organisms should have some basic similarities and at the same time, we should expect certain basic differences because of the obvious differences in cell function and type. In this investigation, you are to use the microscope to examine the cellular makeup of different organisms - plant, animal, and protist. The cells you will observe are: elodea cells, onion cells, cheek cells, and amoeba. You are to look for and record obvious similarities and differences between the cells, and make diagrams of each observation according to the drawing rules. Another aspect of this lab is to examine some of the cellular parts found in certain kinds of cells.

Cell Variety Lab List 2 goals/objectives for this investigation from the background Purpose: 1. 2.

Investigative Question: How does cell type (plant, animal, protist) affect the general shape of the cell, and the types of structures that are visible under a compound light microscope? Variables: Manipulated: Responding: Controlled: Cell Variety Lab (write down the following)

Think back to the Microscopic Organisms Lab. What materials will you need to gather data to answer our investigative question? Materials:

Cell Variety Lab Procedure: *As you write your procedure, be sure to include… Validity Measures: Things done for every trial in the experiment to make sure the results you receive are valid/accurate. Examples of Validity Measures: – Cleaning the lens on the microscope, cleaning lab-ware, using the same brand of equipment, using the same measuring tool. Reliability Measures: Steps taken in the procedure to ensure the results you get are reliable and not due to chance or some other factor. Include a procedure that has the person repeating the applicable steps needed to get multiple data points for each set-up. – You should always include at minimum 3 trials in any experiment.

It can be confusing to tell if something is a validity measure vs. a control variable. Control variables if they are not kept the same between groups/setups will dramatically alter your results. For example: I’m testing how plants react to a specific fertilizer by growing them indoors. I would want both setups to get the same amount of light- otherwise my results will be different than if I gave them various amounts of light. Amount of light is a control variable. Validity measures if they are not kept the same between groups/setups, will not dramatically alter your results (you should come to same conclusion either way)- the results just won’t be as accurate as they would have been if you had included them. For example: I’m testing how plants react to a specific fertilizer by growing them indoors. I would want to make sure I use the same brand of light bulbs- otherwise my results might be slightly different than if I used different brands. Brand of light bulb is a validity measure.