Name

Class

Instructor

Date

Title

Question

What is the sucrose concentrationof different plant tissues?

Hypothesis

Prediction:

Explanation:

An isotonic solutionhas the same concentration of solute as the cell. A hypertonic solutionhas a higher concentration of solute than the cell. A hypotonic solutionhas lower concentration of solute than the cell.

Variables

Independent variable:

Dependent variable:

Operational definition of the dependent variable:

Constants:

Materials

1 potato

1 apple

1 knife

1 ruler

6 beakers

distilled water

5 sucrose solutions

12large test tubes

12 test tube stoppers

Methods

1. Cut 30 uniform pieces of potato and 30 uniform pieces of apple4cm in length. Important: the length should be the same for all pieces.The width and height of the pieces should be the same for all pieces. The instructor will give you guidelines on the dimensions and cutting of the pieces in class.

2. Measure the length of each piece again to be sure they are all 4cm.

3. Record qualitative observations about the tissues.

4. Collectdistilled water and 5 different concentrations of sucrose solutions in 6 labeled beakers.

5. Label two test tubes with the name of each solution and either potato or apple.

6. Place 5 pieces of potato in each of 6 test tubes. Place 5 pieces of apple in each of 6 test tubes.

7. Pour enough of the appropriate solution into the test tubes to cover the pieces.

8. Place the stoppers in the test tubes.

9. Store the test tubes according to your instructor’s directions (1hr at room temperature or 48hrs in a refrigerator).

10. Measure the length of each piece and record it, and record qualitative observations about the tissues.

Conclusion

Was your hypothesis supported?

Why do some pieces increase in length and why do some decrease in length?

Why do some pieces remain the same length?

Why is there a difference in osmosis between the two tissues?

Evaluation

What experimental errors may have occurred?

What errors in data processing or analysis may have occurred?

How could the experiment be improved?

What new experimental questions do you have regarding osmosis or diffusion?

Your lab report will be assessed by the IB rubric below. Please read the rubric.

The IB assessment will be included in the AIS assessment.

IB Assessment: Data Collection and Processing – DCP

Levels/marks / Aspect 1
Recording raw data / Aspect 2
Processing raw data / Aspect 3
Presenting processed
data
Complete/2 / Records appropriate
quantitative and
associated qualitative raw data, including units and uncertainties where relevant. / Processes the quantitative raw data correctly. / Presents processed
data appropriately and, where relevant, includes
errors and uncertainties.
Partial/1 / Records appropriate quantitative and associated qualitative raw data, but with some mistakes or omissions. / Processes quantitative
raw data, but with some mistakes and/or omissions. / Presents processed data appropriately, but with some mistakes and/or omissions.
Not at all/0 / Does not record any appropriate quantitative raw data or raw data is
incomprehensible. / No processing of
quantitative raw data is carried out or major mistakes are made in processing. / Presents processed
data inappropriately or
incomprehensibly.

AIS Assessment

Title / Completely / Partially / Insufficient
Title summarizes and states the purpose of the experiment. / 2 / 1 / 0
Problem/Question and Hypothesis / Completely / Mostly / Partially / Insufficient
Specific problem or question is stated and a specific hypothesis and explanation are provided. / 3 / 2 / 1 / 0
Variables / Completely / Mostly / Partially / Insufficient
All variables are clearly identified: independent, dependent, constants, and/or operational definition. / 3 / 2 / 1 / 0
Results / Completely / Mostly / Partially / Insufficient
IB Assessment / 6-5 / 4-3 / 2-1 / 0
Conclusion / Completely / Mostly / Partially / Insufficient
Explains the results in terms of the hypothesis. / 3 / 2 / 1 / 0
Evaluation / Completely / Mostly / Partially / Insufficient
Evaluates the experiment critically and offers extensions to the experiment. / 3 / 2 / 1 / 0
Format / Completely / Partially / Insufficient
Follows lab report template. / 2 / 1 / 0

Total ___ / 22 = DCP ___