Grades 9-12 Performance Task
Contributed by: New York State Education Department (NYSED)
Developed through University of Buffalo and NORC (1991)

Description:

Students will design and carry out an experiment to test the effects of two variables (time and concentration) on diffusion of potassium permanganate into potato cubes.

This task assesses students' abilities to state a hypothesis, develop procedures for investigation, develop a plan for recording and organizing observations and data, observing and collecting data, drawing an appropriate graph, and drawing consistenc conclusions based on scientific principle.

This task is designed to take students approximately 80 minutes to complete - 30 minutes to complete Part A (Experiment Design) and 50 minutes to complete Part B (Experiment Report).

Overall Task Content Area:

Life Science

Specific Knowledge Areas:

The cell

• conducting investigations
• using equipment
• gathering, organizing, and representing data
• formulating conclusions from investigational data
• applying scientific principles to develop explanations and solve new problems

National Science Education Standards:

12 A SI 1: Abilities necessary to do scientific inquiry: Grades 9-12
1.2 Design and conduct scientific investigations. Designing and conducting a scientific investigation requires introduction to the major concepts in the area being investigated, proper equipment, safety precautions, assistance with methodological problems, recommendations for use of technologies, clarification of ideas that guide the inquiry, and scientific knowledge obtained from sources other than the actual investigation. The investigation may also require student clarification of the question, method, controls, and variables; student organization and display of data; student revision of methods and explanations; and a public presentation of the results with a critical response from peers. Regardless of the scientific investigation performed, students must use evidence, apply logic, and construct an argument for their proposed explanations.

1.3 Use technology and mathematics to improve investigations and communications. A variety of technologies, such as hand tools, measuring instruments, and calculators, should be an integral component of scientific investigations. The use of computers for the collection, analysis, and display of data is also a part of this standard. Mathematics plays an essential role in all aspects of an inquiry. For example, measurement is used for posing questions, formulas are used for developing explanations, and charts and graphs are used for communicating results.

1.4 Formulate and revise scientific explanations and models using logic and evidence. Student inquiries should culminate in formulating an explanation or model. Models should be physical, conceptual, and mathematical. In the process of answering the questions, the students should engage in discussions and arguments that result in the revision of their explanations. These discussions should be based on scientific knowledge, the use of logic, and evidence from their investigation.

12 C LS 1: The cell: Grades 9-12
1.1 Cells have particular structures that underlie their functions. Every cell is surrounded by a membrane that separates it from the outside world. Inside the cell is a concentrated mixture of thousands of different molecules which form a variety of specialized structures that carry out such cell functions as energy production, transport of molecules, waste disposal, synthesis of new molecules, and the storage of genetic material.

(Use the "hot" link on the PALS home page to check the full text of related National Science Education Standards, if desired.)

National Council of Teachers of Mathematics:

DAP1: Formulate questions that can be addressed with data and collect, organize, and display relevant data to answer them:
Grades 9-12 l. understand the meaning of measurement data and categorical data, of univariate and bivariate data, and of the term variable
Grades 9-12 m. understand histograms, parallel box plots, and scatter plots and use them to display data

DAP2: Select and use appropriate statistical methods to analyze data :
Grades 9-12 h. for bivariate measurement data, be able to display a scatter plot, describe its shape, and determine regression coefficients, regression equations, and correlation coefficients using technological tools

AL4: Analyze change in various contexts:
Grades 9-12 f. approximate and interpret rates of change form graphical and numerical data

PS2: Solve problems that arise in mathematics and in other contexts:
Grades 9-12

REP3: Use representations to model and interpret physical, social, and mathematical phenomena:
Grades 9-12

General Instructions to the Teacher:

This task is designed to take students approximately 80 minutes to complete.

Students will be working individually during this exercise.

Students should be ready to work as soon as the period begins. The materials should be set out at each lab station, if possible. A central supply area, if needed, should be easily accessible. All supplies should be clearly labeled.

Materials for "Diffusion":

At each station students will need:

• 2 firm potatoes
• Metric ruler (30 cm)
• 3 small beakers
• 1%, 5%, and 10% solutions of potassium permanganate (in beakers).
• Forceps
• Scalpel
• Stopwatch/clock
• Paper towels
• Experiment Display Sheet
• Waste container
• Graph paper

Advance Preparation:

None

Safety:

• Caution: When using scalpel, slice away from fingers to avoid cuts. Handle potato cubes with forceps only.
• Be careful.
• Teachers and students should always exercise appropriate safety precautions and utilize appropriate laboratory safety procedures and equipment when working on science performance tasks.

Extensions/Modifications:

None