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AP Environmental Science

Mr. Grant

Lesson 66

Lab: Soil Salinization

Part 2

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Objectives:

• Students will conduct an experiment to investigate how salinization affects germination of crop seeds, then determine at what salt concentration seeds no longer germinate.

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APES - Salinization Lab

Purpose

To involve students in a real world scientific investigation in which they design an experiment to determine how the concentration of salt in water affects the germination rate of seeds.

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APES - Salinization Lab

What to turn in:

Hypothesis

Data Table

Graphs 1 & 2

Analysis Questions #1-10

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APES - Salinization Lab

APES - Salinization Lab Hand-In

Name: ______________________________________________________________

Hypothesis:

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APES - Salinization LabSALINIZATION LAB DATA TABLE

DATA TABLE 1: DAILY LOG

Observation Number Date Label Number of Seeds

Germinated Number of Seeds with

No Growth Comments

1 Control 1.0 2.0 3.0 4.1 4.2 4.4 5.0

2 Control 1.0 2.0 3.0 4.1 4.2 4.4 5.0

3 Control 1.0 2.0 3.0 4.1 4.2 4.4 5.0

4 Control 1.0 2.0 3.0 4.1 4.2 4.4 5.0

5 Control 1.0

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APES - Salinization Lab

SALINIZATION LAB DATA TABLE DATA TABLE 2: Summary of Results

Label Number of Seeds

Used

Amount of Salt

Solution, ml

Concentration of Salt

Solution

Total Number of

Seeds Germinated

Total Number of Seeds with No growth

% Gernination

Control 0.0

1.0 1.0

2.0 2.0

3.0 3.0

4.1 4.1

4.2 4.2

4.4 4.4

5.0 5.0

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APES - Salinization Lab

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APES - Salinization LabAnalysis Questions

1) What is the control group in this experiment?

2) What is the dependent variable in this experiment?

3) What is the independent variable in this experiment?

4) Does there seem to be a relationship between the number of seeds which germinated and the concentration of the salt water? If so, what is that relationship?

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APES - Salinization Lab1) Does there seem to be a relationship between the % that germinated and the concentration

of the salt water? If so, what?

2) Did your experiment support your hypothesis? Explain.

3) Can you think of any errors that might have occurred that would invalidate your experiment? If so what were they and how might they be corrected?

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APES - Salinization Lab

1) Explain why increasing levels of salt concentrations affect seed growth and why irrigation seems to be the main cause of this. (Use other sources, if necessary, but cite them.)

2) Do you think all seeds would be affected in similar ways as the ones you used?