Ap biology osmosis hhhhhhhhhhhhhhhhhh
Practical 1- An experiment to observe the features of an Onion Cells
Method:
Gather all equipment that will be used for the experiment and check that they are clean and undamaged.
Using forceps, peel the membrane from the underside of a small piece of onion.
Place the membrane flat on a clean, glass slide and add one drop of iodine solution.
Use a pin to carefully lower the cover slip over the slide, ensure there are no air bubbles before the use of the slide.
Set the microscope to its lowest power objective lens (x4) and make sure it is in line with the optical tube, also that the microscope light is turned on.
After preparation of the slide and microscope, carefully place the slide onto the microscope stand.
Looking from eye-level of the stand, lower the tube using the coarse focus know until the end of the objective lens is just about the slide (ensure you do this with care as to not break the slide).
Look through the eyepiece at your slide and turn the fine focusing knob as to bring the image into focus (be able to see onion cell clearly).
Change the objective lens for a higher magnification on your sample (x10, x40, x1000) as to make out things such as its nucleus.
Once you have achieved a clear image of your cell record what you have found (list/diagram).
Apparatus:
Onion
Iodine
Forceps
White tile
Slides and cover slips
Microscope
Scalpel
Practical 2- An experiment to observe the features of an Cheek Cells
Method:
*only use your own cheek cells and dispose of swab and slide after experiment*
Gather all equipment that will be used for the experiment and check that they are clean and undamaged.
Use a cotton swap to take a smear of the cells from the inside of your own cheek.
Gently wipe the cheek smear onto a clean, glass slide. Try get it central to the slide and be careful not to break the slide.
Afterwards place the used cotton swab into a beaker of detergent to stop the spread of infection.
Add one drop of methylene blue on
Method:
Gather all equipment that will be used for the experiment and check that they are clean and undamaged.
Using forceps, peel the membrane from the underside of a small piece of onion.
Place the membrane flat on a clean, glass slide and add one drop of iodine solution.
Use a pin to carefully lower the cover slip over the slide, ensure there are no air bubbles before the use of the slide.
Set the microscope to its lowest power objective lens (x4) and make sure it is in line with the optical tube, also that the microscope light is turned on.
After preparation of the slide and microscope, carefully place the slide onto the microscope stand.
Looking from eye-level of the stand, lower the tube using the coarse focus know until the end of the objective lens is just about the slide (ensure you do this with care as to not break the slide).
Look through the eyepiece at your slide and turn the fine focusing knob as to bring the image into focus (be able to see onion cell clearly).
Change the objective lens for a higher magnification on your sample (x10, x40, x1000) as to make out things such as its nucleus.
Once you have achieved a clear image of your cell record what you have found (list/diagram).
Apparatus:
Onion
Iodine
Forceps
White tile
Slides and cover slips
Microscope
Scalpel
Practical 2- An experiment to observe the features of an Cheek Cells
Method:
*only use your own cheek cells and dispose of swab and slide after experiment*
Gather all equipment that will be used for the experiment and check that they are clean and undamaged.
Use a cotton swap to take a smear of the cells from the inside of your own cheek.
Gently wipe the cheek smear onto a clean, glass slide. Try get it central to the slide and be careful not to break the slide.
Afterwards place the used cotton swab into a beaker of detergent to stop the spread of infection.
Add one drop of methylene blue on