Required Practical

Question 1

How do you prepare a root tip cell squash?

Answer 1

1. Add HCL to a boiling tube (enough to cover the tip) and out this in a water bath at 60C
2. Use scalpel to cut 1cm from the tip as this is where growth occurs and therefore mitosis
3. Transfer the root tip into the tube and keep it in there for around 5 mins
4. Use tweezers and remove the tip from the tube and rinse well with cold water. Leave to dry on a paper towel
5. Place it on a microscope slide and cut 2mm from the very tip. Remove the rest
6. Use a mounted needle to break the tip open and spread the cells out
7. Add a few drops of stain and leave for a few mins
8. Place a cover slip over the cells and put a piece of folded filter paper on top. Push down firmly to squash the tissue so light can pass through
9. Look through the microscope to see the stages of mitosis

Question 2

How do you use/prepare an optical microscope?

Answer 2

1. Clip the slide you’ve prepared onto the stage
2. Select the lowest powered objective lens
3. Use the coarse adjustment knob to bring the stage up to just below the lens
4. Look down the eyepiece and use the CAK to move the stage downwards until the image is roughly in focus
5. Use the fine adjustment knob to get a clearer image and swap to a higher magnification