Microscopes and measuring cellsIB MYP Biology: Mind map

Exam questions on Microscopes and measuring cells

1. A student prepares a slide of onion skin cells and views it with a light microscope. The eyepiece lens is marked ×10 and the objective lens she selects is marked ×40.
   Outline how the student should use the objective lenses and the focus knobs to obtain a clear image.2 marks
2. A student photographs a human cheek cell through a microscope. The cell in the photograph is 45 mm long. The actual length of the cell is 0.03 mm.
   A second diagram of the same cell is drawn at a magnification of ×400. Calculate the length of this diagram in millimetres.2 marks
3. A student wants to compare the size of onion skin cells with human cheek cells. She prepares a slide of each, views both at the same magnification (×400) and makes a labelled drawing of one cell from each. She then measures the length of each drawing in millimetres.
   State a testable hypothesis for the student's investigation, with a scientific reason, and identify the dependent variable.3 marks