Question

Review Questions 1 Why did you have to calibrate the ocular ruler at different total magnifications? In order to measure a secinrens rolate distance " the lines on the ocular nor. * You measure the length of a cell at 400x total magnification and determine it is 10 micrometers long. What is the length of this cell in millimeters? What is the length of this cell if you measure it at 1000X total magnification? Explain your reasoning 3. The figure below shows an image of a cell, magnified with the 10X objective, lined up on the ocular ruler. Ocular Ruler 0 10 20 30 40 50 60 70 80 90 100 bluedoor, LLC What is the total magnification when using this objective? Explain your reasoning. How long is the cell in the figure measured with the ocular ruler? Using this measurement and showing your work, determine the length of the cell in millimeters and micrometers.

Answer 1

1. Why did you have to calibrate the ocular ruler at different total magnifications?

Answer) The ocular ruler is present inside the ocular lens but it will not change the size when the objectives are changed. In simple words, the marks on the ocular ruler are different distances apart depending on the magnification used on the microscope. So, the ocular ruler must be calibrated for each objective at different total magnification.

2. You measure the length of a cell at 400V total magnification and determine it is 10 micrometers long

a) What is the length of this cell in millimeters?

Answer) Length of a cell = 10 micrometers (µm)

We know that, 1 µm = 0.001 mm

So, length of cell in millimeters (mm) = 10 * 0.001 mm or 10/1000 mm = 0.01 mm.

Hence, the length of the cell in millimeters is 0.01 mm.

b) What is the length of this cell if you measure it at 1000X total magnification? Explain your reasoning.

Answer) The values provided in the question are as follows:

At 400X the total magnification of a cell = 10 micrometers

The formula to calculate the length of the cell at 1000X is as follows:

length of cell at 1000X = (length of cell at 400X) * (magnification at 400X)/ (magnification at 1000X)

Using the values provided in the question,

length of the cell at 1000X = 10 µm * 400/1000 = 4 µm

Hence, the length of the cell at 1000X is 4 µm.