ONLINE LABORATORY MANUAL FOR bILB 365 PLANT PHYSIOLOGY

Leaf surface area is fundamental for experiments in plant physiology. 

  A. Paper–weighing (fresh leaves)

1. Detach all the lobes from the leaf and check to see whether they all can fit on a single printing paper  without touching each other. 
2. Use a ruler to the dimensions  of each side (cm) of the printing paper/s. (record data in notebook)
3. Fold the printing paper/s a few  times so it would fit onto the digital scale and measure the weight of the  paper/s (g). (record data in notebook)
4. Lay each lobe on the paper so  that they do not touch each other on the same paper/s that was measured. 
5. Trace each lobe using a pencil on the paper as accurately as possible. 
6. Cut out each traced lobe out of  the printing paper/s using a scissors as accurately as possible. 
7. Place all cuttings on the  digital scale and measure the weight of them together. (record data in   notebook)
8. Compute the printing paper  surface area (cm²) from the measurements already taken.
9. Compute the leaf surface area (cm²) using the formula : 

Surface Area of cuttings(cm²) = weight of paper cuttings(g)✕surface are of whole paper(cm²)÷weight of cuttings (g)

            10. Record the calculated surface  area (cm²) in the notebook.

  B. Image analysis with ImageJ (dried leaves/lobes)

1. Use a ruler to draw a 1cm scale on a white printing paper.

2. After press drying, place lobes on the printing paper making sure they are not touching.

3. Use a device (cell phone, scanner) to take a picture of the paper with the lobes. 

4. On a device (laptop) open the picture in ImageJ,s et the scale from the ruler scale (1cm) that was drawn (Zoom into image→Click straight line tool→Draw a line over the scale→Analyze → Set Scale).

5. Covert image to grey scale. (Image→Type→8-bit) 

6. Threshold the background of the image.( Image→Adjust→Threshold→Dark background→Apply)

7. Use the magic wand tracing tool and roi manager to measure the lobes surface area. (Magic wand tool→Select a lobe→Analyze→Tools→ROI manager→Add→Repeat for all leaves→Click measure in the ROI manager) 

8. Add together all of the measurements to get the full surface area of the leaf(cm²). (record data in notebook) 

9. Take a screen shot from Image J showing surface area of the leaf lobes. 

10. Record the calculated surface  area(cm²) in the notebook.

 https://imagej.net/ij/download.html 

Analys>Set scale>known unit 1>cm

Image>type>8bit

Image>adjust>threshold

Analyse>tools>ROI manager

Laboratory template for ALL labs.

https://docs.google.com/document/d/19dbAz7XBsVNEu5qNT1lmWEHiXeuq5G_q/edit?usp=sharing&ouid=108146794436934394031&rtpof=true&sd=true

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1. Six solutions were prepared:  three salt solutions and three sugar solutions at concentrations of 1g,  2g, and 3g.
2. A thin epidermal peel was  obtained from an onion bulb. A small square (1cm x 1cm) was cut using a scalpel.
3. The sample was placed on a  clean glass slide.
4. A drop of the 3g salt solution was added, and a cover slip was gently placed over it to avoid air  bubbles.
5. The specimen was immediately  placed under the microscope at 40x magnification.
6. A single cell was chosen, and the stopwatch was started as soon as the solution made contact.
7. The time taken for the cell to become fully plasmolyzed (membrane fully detached from the cell wall) was  recorded.
8. Steps 2–7 were repeated for each concentration of salt and sugar solution. Each concentration was tested on two separate cells for reliability.
9. Data was recorded in tables and later used to generate a comparative bar graph.

https://www.youtube.com/watch?v=Iv7eGCPVaAk