Course title

Pre-requisite

Course description

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Name of course:† †Biology 1-2 v (virtual)

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Duration of study:†††††††††††††† one year††††††††††††††††††††††††††††††††††††††††††††††† Virtual via Edgenuity (copyright date; 2020)

(full year; one semester; trimester) ††††††††††††††††††††††††††† †††††††††††††††††††††††††††††††

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Approximately how many hours per week do students spend conducting hands-on laboratory experiments in this course?

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1-2 hours

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Please provide a list of the laboratory experiments or projects you do that require manipulation of equipment.

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Lab/Using a Dichotomous Key: Explore how dichotomous keys are used to identify unknown organisms through a laboratory experiment

Virtual Lab/Dichotomous Lab: Use a virtual lab to identify a set of unknown organisms

Virtual Lab/Natural Selection: Explore natural selection through a virtual experiment on speckled moths

Lab/Natural Selection/Beak Lab: Using different beak models to test natural selection through food availability

Virtual Lab/Protein: Explore and manipulate the process of building proteins from the information carried by RNA

Lab:/Diffusion Across a Semi-permeable Membrane: Create a model cell using dialysis tubing and model diffusion

Virtual Lab/Diffusion: Using a virtual lab platform to test different solutions and the rate of diffusion

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List all lab equipment used; including but not limited to household items (for example; microscope; beakers; ramps; dissection equipment; etc.)

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Virtual Lab/Dichotomous Lab: Computer access; student handouts; printed or online viewable pictures

Virtual Lab/Natural Selection: Access to online simulation and student graphic organizer

Lab/Natural Selection/Beak Lab: Paper clips; chopsticks; fork and spoon. At least 3 types of beans. Small cups. Student handout.

Virtual Lab/Protein: Computer access to the virtual lab and student handout

Lab:/Diffusion Across a Semi-permeable Membrane: Dialysis tubing; small beaker/cup; inside solution (glucose solution); outside solution (water); urinalysis test strips

Virtual Lab/Diffusion: Access to online lab and student handout.

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Using standard Scientific Method outlined by the following questions; describe one typical laboratory assignment associated with this course.

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What is the effect of the molecule size of a material on its ability to diffuse across a semipermeable membrane?

Hypothesis: If molecules are small enough; then they will diffuse across a semipermeable membrane because they will be able to pass through its tiny openings.

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Describe the experiment you performed to prove or disprove your hypothesis. List all essential materials. Describe each step you performed in the experiment.

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Materials:

• Droppers
• †Stirring rod
• †Seven test tubes
• †Two 500 mL beakers
• †Hot plate
• †Distilled water
• †Two lengths of dialysis tubing; each 15 cm long
• †String
• †Starch solution
• †Lugol?s solution (starch indicator)
• †Glucose solution
• †Benedict?s solution (glucose indicator)

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Procedures:

Step 1:

a) Label three test tubes ?Water;? ?Starch;? and ?Glucose.? Add ten drops of water; ten

drops of glucose solution; and ten drops of starch solution respectively.

b) Put ten drops of Lugol?s solution into each of the test tubes.

c) Gently swirl the contents of all three test tubes.

d) In your data table; record any color changes; which indicate that starch is present. (If

the indicator solution works properly; only the test tube with the starch solution should

show a change.) Keep these test tubes for reference during Step 4.

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Step 2:

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a) Tie a knot in one end of a length of dialysis tubing.

b) Hold the tubing with the knotted end down. Carefully fill the tubing with starch solution so

that the tube is half full.

c) Tie a knot in the top end of the tubing.

d) Rinse the tubing with water. (It is best to use distilled water; at least for the final rinse.)

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Step 3:

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a) Fill a 250 mL beaker with 150 mL of distilled water. Add ten drops of Lugol?s solution to the

beaker; and mix with a stirring rod.

b) Place the tubing into the beaker. Observe the solution in the beaker and the dialysis tube;

record your observations in the data table.

c) Wait 15 minutes. Note the color of the solution in the beaker and the dialysis tube; record the

results in the data table.

d) Did starch diffuse through the membrane? Record your answer and reason in the data table

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Step 4:

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a) Label three test tubes ?Water;? ?Starch;? and ?Glucose.? Add ten drops of water; ten drops of

glucose solution; and ten drops of starch solution respectively.

b) Put ten drops of Benedict?s solution into each of the test tubes.

c) Place the test tubes in a water bath on the hot plate. Heat for five minutes.

d) In your data table; record any color changes; which indicate that glucose is present. If the

indicator solution works properly; only the test tube with glucose solution should show a

change. Keep these test tubes for reference during step 6.

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Step 5

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Repeat steps 4a through 4d exactly except with the glucose solution.

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Step 6:

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a) Fill a 250 mL beaker with 150 mL of distilled water. Add ten drops of Benedict?s solution to

the beaker and mix with a stirring rod.

b) Place the tubing into the beaker. Observe the solution in the beaker and the dialysis tube.

Record your observations in the data table.

c) Wait fifteen minutes. Transfer ten drops of the solution in the beaker to a test tube.

d) Place the test tube in a hot water bath; and wait for five minutes. Note the color of the

solution in the test tube taken from the beaker. Record the results in the data table.

e) Did glucose diffuse through the membrane? Record your answer and reason in the data

table.

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Describe the results of your experiment or study. Use graphs and charts where appropriate.

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DATA & OBSERVATIONS

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Table 1: Indicator Tests

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Color Change Due to Lugol?s Solution

Color Change Due to Benedict?s Solution

Distilled Water

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-

Starch Solution

+

-

Glucose Solution

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+

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Table 2: Diffusion Tests

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Test for Diffusion of Starch

Test for Diffusion of Glucose

Color of Solution in Dialysis Tube

Initial Color: Clear

Color after 15 mins: Black

(Not Observed)

Color of Solution in Beaker

Initial Color: Yellow

Color after 15 minutes: Yellow

Initial Color: Light Blue

Initial Color After 5 mins boiling: Red

Was there diffusion?

Y/N Reason: The beaker solution never turned black; so Lugol?s did not indicate starch.

Y/N Reason: Because the beaker solution turned red; Benedict?s indicates glucose

Explain your data or results. Give an analysis of your experiment.

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The results of the experiment show that glucose; the smaller molecule; was able to diffuse across the semi-permeable membrane. Starch; the larger molecule; was unable to diffuse across the membrane. The particles of the Lugol?s solution; however; were small enough to diffuse into the tubing.

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Write a conclusion for your study. Was your hypothesis supported or refuted?

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The hypothesis is ?If a material is small enough; then it will diffuse across a semi- permeable membrane because it will be able to pass through the tiny openings in the membrane.? This hypothesis is supported by the data collected in the laboratory. The glucose; which is small enough; diffused from the high concentration inside the tubing to the low concentration outside of the tubing. The starch; which was too big; did not diffuse out of the cell. To improve the results of this experiment; performing additional trials would help to show that consistent results were obtained. To further explore the diffusion of materials; saline and other types of solutions could be tested.

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School country

School state

School city

School / district Address

School zip code

Requested competency code

Date submitted

Approved

Approved competency code

• LBIO
• Biology

Approved date

Deferred Reason

In order to be reviewed as a laboratory science; we will need a list of physical laboratory experiments completed for this course and number of hours students spend doing laboratory assignments each week.

Online / Virtual