Mean length onion cells

Question 1

first four bullet points

Answer 1

•Place ruler on microscope stage
•Focus on the scale on the ruler
•measure width of feild of view in millimetres
•Replace ruler with slide

Question 2

Second bullet points

Answer 2

•focus on cells
•use same magnification
•count number of cells that fit lengthwise across feild of veiw
•calculate mean length of onion cells by multiplying width of feild veiw by number of cells