Experiment+Report+B_Leek+cells


 * Estimation of the osmotic concentration of Leek cells**
 * Biology Experiment Report**
 * By Sun Fangda (22) Class 311**


 * Aim:**

To estimate the approximate osmotic concentration of the leek stem cells


 * Prediction:**


 * The leeks that were soaked in the salt solutions with a lower percentage of salt (hypotonic solution) will have a larger increase in the length of the inner surface and the weight, due to osmosis.
 * The leeks that were soaked in the salt solutions with a higher percentage of salt (hypertonic solution) will remain the same or decrease in the length of the inner surface and the weight, due to osmosis.
 * Apparatus:**


 * Razor blade/ scalpel, white tile
 * 5 Petri dishes
 * Forceps
 * Distilled water
 * 1%, 2%, 4%, 7%, 10% salt solution
 * Chinese leeks (Allium tubersosum)
 * Stop watch
 * Vernier calipers
 * Thread
 * Labels
 * Methods:**


 * 1) Cut the inflorescence stalk of the Chinese leek to obtain a length of 3 cm and weigh.
 * 2) Cut the strip longitudinally as shown in the diagram below to obtain 4 equal quarters. Repeat till you have obtained 6 strips.
 * [[image:webkit-fake-url://B7A9303F-C4B5-44EB-ADB8-C0F9506CC575/pastedGraphic.pdf caption="pastedGraphic.pdf"]] ||
 * pastedGraphic.pdf ||


 * 1) Place one strip in a Petri dish of distilled water, one each in 1%, 2%, 4%, 7% and 10% salt solution.
 * 2) After 20 minutes, record the **length** of the inner surface and weigh. **Draw** the results in a table and graph. Explain how the length was measured.


 * **Assumptions:**


 * The methods assumed that every strip of the leek has the same water concentration.
 * The methods assumed that every strip of the leek has the same length.
 * The methods assumed that every strip of the leek has the same weight.


 * **Precautions**


 * After cutting the leek into the 6 strips, measure each of the weight and the length of the inner surface.
 * Place the strips of the leek into the different labeled petri dish before and after measuring the weight and the length of the inner surface to differentiate them.
 * To try to have the same amount of the salt solution in each of the petri dishes.
 * As the strips of the leek will float in the salt solution, turn the inner surface of the leek downwards, to be in contact with the salt solution, so that osmosis can happen between the solution and the inner surface of the leek.
 * Results:**


 * **Table of results:**


 * ||  || **Length** || **/cm** ||   ||   || **Weight** || **/g** ||   ||   ||
 * || 0 min || 20 min || difference || % difference || 0 min || 20 min || difference || % difference ||  ||
 * **0%** || 3.1 || 4.1 || 1.0 || 32.2 || 0.26 || 0.33 || 0.07 || 26.9 ||  ||
 * **1%** || 3.2 || 3.6 || 0.4 || 12.5 || 0.25 || 0.30 || 0.05 || 20.0 ||  ||
 * **2%** || 3.5 || 4.1 || 0.6 || 17.1 || 0.18 || 0.25 || 0.07 || 38.8 ||  ||
 * **4%** || 3.1 || 3.5 || 0.6 || 19.3 || 0.25 || 0.21 || 0.04 || -16.0 ||  ||
 * **7%** || 3.0 || 3.4 || 0.4 || 13.3 || 0.21 || 0.26 || 0.04 || 19.0 ||  ||
 * **10%** || 3.2 || 3.5 || 0.3 || 9.38 || 0.23 || 0.29 || 0.06 || 26.1 ||  ||


 * Graphs:**

Graph of percentage of change in length of the inner surface over the percentage of salt solution


 * Estimation of the osmotic concentration of Leek cells**
 * Biology Experiment Report**
 * By Sun Fangda (22) Class 311**


 * Aim:**

To estimate the approximate osmotic concentration of the leek stem cells


 * Prediction:**


 * The leeks that were soaked in the salt solutions with a lower percentage of salt (hypotonic solution) will have a larger increase in the length of the inner surface and the weight, due to osmosis.
 * The leeks that were soaked in the salt solutions with a higher percentage of salt (hypertonic solution) will remain the same or decrease in the length of the inner surface and the weight, due to osmosis.
 * Apparatus:**


 * Razor blade/ scalpel, white tile
 * 5 Petri dishes
 * Forceps
 * Distilled water
 * 1%, 2%, 4%, 7%, 10% salt solution
 * Chinese leeks (Allium tubersosum)
 * Stop watch
 * Vernier calipers
 * Thread
 * Labels
 * Methods:**


 * 1) Cut the inflorescence stalk of the Chinese leek to obtain a length of 3 cm and weigh.
 * 2) Cut the strip longitudinally as shown in the diagram below to obtain 4 equal quarters. Repeat till you have obtained 6 strips.
 * [[image:webkit-fake-url://465F3E0F-0D9C-47B4-91FF-10C0ACA23A00/pastedGraphic.pdf caption="pastedGraphic.pdf"]] ||
 * pastedGraphic.pdf ||


 * 1) Place one strip in a Petri dish of distilled water, one each in 1%, 2%, 4%, 7% and 10% salt solution.
 * 2) After 20 minutes, record the **length** of the inner surface and weigh. **Draw** the results in a table and graph. Explain how the length was measured.


 * **Assumptions:**


 * The methods assumed that every strip of the leek has the same water concentration.
 * The methods assumed that every strip of the leek has the same length.
 * The methods assumed that every strip of the leek has the same weight.


 * **Precautions**


 * After cutting the leek into the 6 strips, measure each of the weight and the length of the inner surface.
 * Place the strips of the leek into the different labeled petri dish before and after measuring the weight and the length of the inner surface to differentiate them.
 * To try to have the same amount of the salt solution in each of the petri dishes.
 * As the strips of the leek will float in the salt solution, turn the inner surface of the leek downwards, to be in contact with the salt solution, so that osmosis can happen between the solution and the inner surface of the leek.
 * Results:**


 * **Table of results:**


 * ||  || **Length** || **/cm** ||   ||   || **Weight** || **/g** ||   ||   ||
 * || 0 min || 20 min || difference || % difference || 0 min || 20 min || difference || % difference ||  ||
 * **0%** || 3.1 || 4.1 || 1.0 || 32.2 || 0.26 || 0.33 || 0.07 || 26.9 ||  ||
 * **1%** || 3.2 || 3.6 || 0.4 || 12.5 || 0.25 || 0.30 || 0.05 || 20.0 ||  ||
 * **2%** || 3.5 || 4.1 || 0.6 || 17.1 || 0.18 || 0.25 || 0.07 || 38.8 ||  ||
 * **4%** || 3.1 || 3.5 || 0.6 || 19.3 || 0.25 || 0.21 || 0.04 || -16.0 ||  ||
 * **7%** || 3.0 || 3.4 || 0.4 || 13.3 || 0.21 || 0.26 || 0.04 || 19.0 ||  ||
 * **10%** || 3.2 || 3.5 || 0.3 || 9.38 || 0.23 || 0.29 || 0.06 || 26.1 ||  ||


 * Graphs:**

Graph of percentage of change in length of the inner surface over the percentage of salt solution