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.
Cell Variety Lab
(write down the following)
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 lightotherwise 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 bulbsotherwise my results might be slightly different than if I used different brands.
Brand of light bulb is a validity measure.