result of exp2

7/30/2019 Result of exp2

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School-based assessment

Practical related tasks


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Osmosis in Living Tissue

To determine the water potential of potatotissue.


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Curriculum Link

C1 Water for Living

Movement of water in and out of cells by osmosis


4/17

Background


5/17

How can we determine the water potential of

potato tissues?

Potato

1.0 M Sucrose solution

(= 342 g sucrose in 1 L of solution)


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Apparatus and Chemicals


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Procedure (1)

A series of sucrose solution of

different concentration.


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Procedure (2)

Cut potato cylinders into length of 5 cm.

Blot dry the potato cylinders and put them into a Petri dish.


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Procedure (3)

Immerse 2 potato cylinders in

each tube that contains different

concentration of sucrose

solution.

After 40 mins, take out the

potato cylinders, blot dry and

measure the length of the potato

cylinders.


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Result Table

1. Tabulated result :

Notice the position of independent variable,dependent variable in the table.

Units and suitable conversions should be shown

clearly and correctly

Title of the table should be written correctly according

to the aim of the experiment.e.g. Effect of sucrose concentration on thee.g. Effect of sucrose concentration on the

length of potato cylinderlength of potato cylinder.


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Effect of sucrose concentration on the percentage

change in length of potato cylinder

- 3.04.854.84.950.6

- 1.04.954.95.050.4

- 5.04.754.74.850.8

4.6

5.1

5.2

- 7.04.654.751.0

+ 3.05.155.250.2

+ 5.05.255.350

% change in% change in

length of potatolength of potatocylinderscylinders

AverageAverage

ffinal lengthinal length

of potatoof potatocylinderscylinders

(cm)(cm)

FFinal lengthinal length

of potatoof potato

cylinderscylinders

(cm)(cm)

OOriginalriginal

length oflength of

potatopotatocylinderscylinders

(cm)(cm)

concentrationconcentration

of sucroseof sucrosesolutionnsolutionn/ M)/ M)

Key : + increase in lengthKey : + increase in length

-- decrease in lengthdecrease in length


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Graph

Notice the choice of axes

x-axisfor independent variable (unit should be stated)

y-axisfor dependent variable (unit should be stated)

Notice the rule of using short straight lines to join

the points or the smooth curve to join the points Title of graph should be added correctly and related

to the aim of the experiment

e.g. Effect of sucrose solution on the % change in length of potato

cylinders


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Effect on sucrose concentration on the %Effect on sucrose concentration on the %Effect on sucrose concentration on the %Effect on sucrose concentration on the %

change in length of potato cylinderchange in length of potato cylinderchange in length of potato cylinderchange in length of potato cylinder

-8.0-8.0-8.0-8.0

-6.0-6.0-6.0-6.0

-4.0-4.0-4.0-4.0

-2.0-2.0-2.0-2.0

0 .00.00.00.0

2 .02.02.02.0

4 .04.04.04.0

6 .06.06.06.0

0000 0.20.20.20.2 0.40.40.40.4 0.60 .60.60 .6 0.80.80.80.8 1111 1.21.21.21.2

Concentration of sucrose solution / MConcentration of sucrose solution / MConcentration of sucrose solution / MConcentration of sucrose solution / M

%c

hangeinleng

thofpotato

%c

hangeinleng

thofpotato

%c

hangeinleng

thofpotato

%c

hangeinleng

thofpotato

cylinders

cylinders

cylinders

cylinders


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Laboratory Report Title

Aims

Theory/Background (optional)

Apparatus

Design of experiment

Procedure

Precautions and safety measures

Results (including data and observations)

Discussions (including possible sources of errors andimprovements to be made)

Conclusion

Questions for further thought (optional)


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Assessment CriteriaArea A (Max:10)


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Assessment criteriaArea B (Max:10)


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Assessment CriteriaArea B (Contd)

result of exp2

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