Required Practicles

Question 1

How do you prepare an oninon cell on a slide?

Answer 1

Step1: First take off the thick layer of onion skin
Step2: Now use your thingers to obtain a very thin layer of skin from the onion. One way to do this is by breaking a small piece of onion in half and removing the skin
Step 3: place the sample of onion on the slide and spread it out so there are no folds on the onion
Step4: Place a two or three drops of iodine in on the slide (this is to help us visually see the cells in the microscope).
Step5: Place the small glass cover slip on the slide
Step6: wipe away any left over iodine

Question 2

How do you use a microscope?

Answer 2

You have to focus on the cell by adjusting the magnification and the height of the eye piece

Question 3

Name some things you should do to keep safe while using the equipment

Answer 3

Safety:
• Take care when handling slides and microscope
• Anything that you have put into your mouth should
be placed in disinfectant after use
• Wear gloves if using stains
• Wear eye protection
• Methylene blue is an irritant

Question 4

Name the equipment needed

Answer 4

Apparatus:
• Light microscope
• Lamp
• Microscope slide/Glass slide
• Coverslip
• Methylene blue stain/Iodine
stain
• Pipette
• Paper towel
• Wooden toothpick/ Cocktail
stick
• Onion bulb
• Disinfectant
• Knife & White Tile
• Tweezers
• Forceps

Question 5

How do you find out the percentage in the osmosis required practicle?

Answer 5

% change =
change in mass (g)
Divide
initial mass (g)
X 100
= answer