Scientific Fair Test

Toxic water

We are learning to:• Conduct a fair test investigation following the scientific method in order todetermine the effect of toxic water on seed germination and root growth.

At the end of the investigation students will be able to:

• Determine the effect of toxic water on seed germination and root growth.

• Create a research question and hypothesis based on their prior research.

• Plan and conduct an investigation.• Make observations, record results

and graph.• Make a results statement and

conclusion.

What went down the drain?• Detergents – Soaps• Organic material - Leaf litter and grass cuttings• Pesticides – poison• Run-off water from washing cars• Sewer overflows• Fertilisers• Leaks from cars and trucks• Animal and bird droppings• Septic tank leaks

Investigation

• Today we will prepare for an investigation to look at the effects of water pollution on seed germination and root growth.

• The investigation will run for about five days – depending on germination and root growth.

• Students will work in groups

GroupsGroup 1 Group 2 Group 3 Group 4 Group 5Stephanie (L)TarynJamesIsraelGeorgia

Sharna (L)AugustHarryKarn

Liam (L)CoreyNatasha EmmaJosh

Daniel (L)HunterTaylorDestiny

Briar (L)CainDylanJaden

Get your topic study books, glue stick, pencil, eraser and red pen and move into your groups.

Activity 1• Glue Scientific Investigation Instructions in your topic

book.

• Read through the sheet – at the end you may ask questions for clarifications.

• Be prepared to explain the investigation in your own words. (5 min)

• Look at the information you got from your internet research – Activity 6

Activity 2 – Draft question

• Design a draft research question based on prior discussions and the list of materials.

• Discuss in your group and write up on a piece of scrap paper.

• 4 minutes

Examples:• Does water quality

effect seed germination and root growth?

• What kind of water makes seeds germinate and roots grow best?

• Does water pollution affect seed germination and root growth?

Write:

31-08-2009 Toxic water investigation

• Research question: (Write down the question your group has agreed upon)

Activity 3 - hypothesis

• From your research question comes the hypothesis.

• Now in your group come up with your hypothesis (prediction)

Examples• More seeds will germinate

and roots grow longer in clean water.

• Seeds will not germinate as well in polluted water and the roost will be shorter.

• The water with the most pollution will have the lowest germination and root growth.

Write:

31-08-2009 Toxic water investigation

• Research question:

• Hypothesis (my prediction) (Write down the prediction your group has agreed upon)

Activity 4 – Controlled variables

• Look at the “equipment and materials” and the “things to know”.

• What are the controlled / dependent variables? (What will be the same?)

Controlled variables:• Container size• Absorbent paper• Lettuce seeds• Amount of darkness in

which the seeds germinate

• The place where the seeds germinate

Write:

31-08-2009 Toxic water investigation

• Research question:

• Hypothesis (my prediction)

• Experiment – Controlled variables: (List)

Activity 5 – Independent variables

• Look at the “equipment and materials” and the “things to know”.

• What is the one thing that will be different?

The water quality• Laundry detergent

water• Dish washer water• Soap water• Shampoo water• Oil water• Animal droppings water

Write

31-08-2009 Toxic water investigation

• Research question:

• Hypothesis (my prediction)

• Experiment – Controlled variables:

• Experiment – Independent variable: (List)

Activity 6 - Control

• Identify the control.• The one thing that will show us normal germination and root growth is if we use…..

• Clean tap water.

Write31-08-2009 Toxic water investigation

• Research question:

• Hypothesis (my prediction)

• Experiment – Controlled variables:

• Experiment – Independent variable:

• Experiment – Control:

• Experiment:

Activity 7

• In your groups, read the “lettuce seeds procedure”.

• Discuss what to do – in your own words – do we all agree what to do?

• Now write up in your own words what you will do / how you will set the experiment up.

• Support your buddies.

The experiment

Part 2

The experiment• Today we will be setting up and

running the experiment based on the procedure you wrote up yesterday.

Step 1: Organise the equipment & materials

Each group will get:• 4 x 1.5litre containers • 2 x pollutants• 1 x salt solution• Masking tape for marking• 4 x dishes with lids• 2 x absorbent paper discs • 1 x tweezers• 1 x ruler• 4 x eye droppers• Aluminium foil

Behaviour and safety:

• Work area• Handle of chemicals• Keep fingers out of

mouth and don’t rub eyes

• Wash hands after each session.

Step 2: Water samplesEach group creates their own water samples

• 1 x control - clean water• 1 x salt solution (500ml water, 250ml non-

carbonated water and 250ml salt)• 2 x pollutants (100ml and pollutant)

Label water samples with:• Content • Date• Ratio of the mix

Step 3 • Place an absorbent disc in each of the four

disks / containers• Label the four disks / containers A – Salt solution

B – Pollutant 1C – ControlD – Pollutant 2

Write this information in your topic book

Step 4• Use a clean eye dripper.• Add just enough water (about 4ml) to

wet the absorbent paper in the disk / container marked C

• Do the same for sample A, B and D using a clean eye dripper so that you don’t contaminate your samples.

Step 5• Use the tweezers, select 20 lettuce

seeds and place them on the bottom side of each disk / container.

• Arrange them in rows of 4 or 5• Cover with absorbent paper disk • Place the cover on the disk /

containers.• Carefully wrap each disk in foil

Step 6• Store in room temperature that will

not be disturbed for 5 days.• No direct sunlight or other heat source that will dry the absorbent paper out.

Write:

• Write up the experiment – what you have done.

• Be very specific and detailed

Observation Part 3

• Use the seed germination and root growth recording sheet to record observations.

• Have a pencil and ruler ready

• Lay the ruler on a clean blank paper.

• Carefully unwrap and open the disks / containers

• Count the numbers of seeds that have germinated and record.

• If there is enough root growth to measure use the tweezers to carefully lift.

• The edge of the root is at 0 so only the root is measured.

• Record the lengths of all the roots.

• Calculate the average

• Cover seeds – Leave for 3 more days before observation is repeated.

Interpret the data

InterpretationGraph 1

• Create a graph in which the y axis show the number of seeds germinated over the 5 days and with the x axis showing the different water samples.

Salt w

ater

Oil wate

r

Pure wate

r

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ry 4

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Number of seeds that ger-minated after 5 days

Number of seeds that germinated af -ter 5 days

InterpretationGraph 2

• Create a graph in which the y axis show the measurement of root growth over the 5 days and with the x axis showing the different water samples / pollutants.

Interpretation Result statement

•Write a simple result statement after interpreting the data and studying their observations

Conclusion• Now write your conclusion

with a statement about whether the data supported your original

hypothesis (prediction)

Final assessment task• Use the information you have

gathered and present a summary of the investigation on a display poster.