*Lab #1: the Effects of Soil Salinization on Mung Bean Germination

*Lab #1: the Effects of Soil Salinization on Mung Bean Germination

*Lab #1: The effects of Soil Salinization on Mung Bean Germination

Background information: Pg 226-227 in text. Fact: “Seawater is about 3.4% salt by weight, and it has probably been less than 4% as far back as we have data. If it ever rose to more than 6%, all life in the sea (except possibly some archaebacteria) would be killed.” - Miller. When diluting a solution, remember the formula V1C1 = V2C2 (Volume 1 x Concentration 1 = Volume 2 x Concentration 2)

*Purpose: What level of salinization will cause mung bean seed germination to change visibly?

*Hypothesis: Write as an IF/Then statement. What do you think is the answer to the purpose question? GUESS! Make your guess as specific as possible.

*Procedure: Design an experiment which will quantitatively display the relationship between salt concentration and seed germination and growth. Write as a numbered set of directions. Include quantities of materials used. Be specific. Remember that the goal for this section is to make the directions so clear that a total stranger could replicate your experiment perfectly. (Replicability!) Be sure to include a control with your experiment. Be sure to include a description of how you will determine a change in germination.

*Data: Create a meaningful chart, graph or table to record your findings in a clear manner.

*Analysis: Write out these questions and their answers in your lab notebook.

1. Identify the independent and dependent variables in your procedure.

2. Identify the factors which were held constant between the control and experimental groups.

3. Explain why you chose to work with the particular salt solutions that you did. How did they reflect real-world situations?

4. Describe one real life situation in which salinity might change dramatically within an ecosystem.

*Conclusion: Was your hypothesis supported or refuted? Justify your conclusion in a descriptive paragraph using data for support. Describe possible design flaws in your procedure and explain how they might have affected your outcome. (A design flaw is a limitation in the design of the experiment that could have changed the outcome of your procedure. There are ALWAYS possible design flaws. You should be able to identify at least three. These aren’t necessarily things you know you did wrong – they’re just things that MIGHT have gone wrong and affected your outcome. Miscalculations or failure to follow directions are human mistakes. Anything that limits precision is a design flaw.)

PRELAB: Lab #1: The effects of Soil Salinization on Mung Bean Germination

Directions:

  1. Read both sides of this sheet completely.
  2. In the space below, plan your procedure to test the purpose question. You may either write out your plan in a series of steps OR draw a diagram which includes everything you will need to set this lab up in class.
  3. In your drawing, label the independent variable, all controlled variables, the experimental group(s) and the control group(s).

Materials at your disposal:

NaCl solution (10% by volume), water, petri dishes, graduated cylinders, beakers, mung bean seeds, paper towels, foreceps, hand lenses, stirring rods, electronic balance, labeling stickers.