25 Pointsdate Turned In

Worksheet 3Name:

PlasmolysisSection:

25 pointsDate Turned In:

Introduction:

1. (4 pts) Draw a concept map that includes the following terms: plasmolysis, salt, water, movement, plant cell membrane, plant cell wall. Use each term at least once. Make sure the linking phrases you use are appropriate. Your Freeman textbook (p. B:28) has a guide to making concept maps.

Materials and Methods:

2a. (2 pts) What method did your group or class use to measure plasmolysis?

2b. (2 pts) Why was it important to decide on the method to use for collecting your data BEFORE you performed the experiment?

2c. (2 pts) Explain the importance of “replicates” to a well-designed experiment.

Results:

3. (5 pts) Use Prism to create a bar graph for the following data:

(column A) number or percent of Elodea plasmolysis at minimal concentration of NaCl,

(column B) number or percent of Elodea plasmolysis at the same concentration of sucrose,

(column C) number or percent of Algae plasmolysis at the same concentration of NaCl as in column A.

Make sure to:

a) independently label X- and Y- axes (do not copy what is written above)

b) provide an accurate figure legend, as described on p. 18 of your lab manual

c) include your typed name and date on your figure

Graphing and figure legends

There are several important factors to consider when constructing a scientific graph. First, properly labeling and setting up your graph requires you to distinguish between dependent and independent variables. Independent variables are independent of other variables in an experiment. Usually, you control this variable. Dependent variables are dependent on other variables in an experiment. Usually, this is the measure you are interested in investigating in an experiment. Independent variables are always on the x-axis; dependent variables are on the y-axis. Second, data points may or may not be connected; sometimes, a best fit line is often included to show general trends in the data. To help you consider how to make your graph, refer to the flowchart on p. 39 of your lab manual:

4a. (5 pts) Use Prism to graph the relationship between NaCl molarity and the number or percent of Elodea cells undergoing plasmolysis.

Make sure to label x and y –axes appropriately, include a proper figure legend, and add your name & date.

4b. (2 pts) Which type of graph did you choose to best present your data? Why?

Discussion:

5. (2 pts) Did sucrose produce the same reaction as sodium chloride? Explain why or why not.

6. (2 pts) Did/Should the saltwater plant have the same reaction as Elodea? Explain why or why not.