Microscope calculations - MissHaynes-Science

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Microscope calculations

1. Converting between units

You only need to remember two sums to convert between any units.

Basic conversions

Complete the table below

Example 1 Example 2

Convert 2350nm Convert 143mm

2350nm ÷ 1000 = 0.2350μm 143mm x 1000 = 143,000μm

0.2350μm ÷ 1000 = 0.0002350mm 143,000 μm x 1000 = 143,000,000nm

Millimetre Micrometre Nanometre

1580

0.23

174

3

0.008

0.5

18

23

8

0.1

5

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2. The equation triangle This equation triangle gives you 3 equations. What are they?

Image =

Actual =

Magnification =

Basic calculations

1. A human hair is 25μm and is observed at x400.

a) Calculate the size of the image in μm.

b) Calculate the size of this image in mm.

2. A bacterial cell is drawn 1000mm long. It was viewed at a magnification of x500.

a) Calculate the size of the bacteria in mm.

b) Calculate the size of the bacteria in μm.

3. A mitochondria was drawn 20mm long. Its actual size is 2μm.

a) Calculate the size of the image in μm

b) Calculate the magnification used.

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3.Calculating magnification.

Equation needed to calculate Magnification =

Questions

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4.Calculating actual size – measure the scale bar

Equation needed to calculate Actual size =

Questions

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5. Calculating actual size – use the scale bar to calculate magnification first

Equations needed - Magnification =

Actual size =

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6. In context – animal cell

For questions 2-5 calculate the answers in μm

N/A

Nucleolus

N/A

N/A

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In context – plant cell

For uestions 2-5 calculate the answers in μm

N/A

N/A

I ____________

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7. Using micrographs

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Exam questions – standard demand The image below shows part of a root from a cress plant.

(a) What type of microscope was used to create the image above?

___________________________________________________________________

(1)

(b) The magnification of the cress root in the image above is × 210.

There are 1000 micrometres (μm) in a millimetre (mm).

Calculate the real length of the root hair, X.

Give your answer in micrometres (μm).

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

Real length X = ____________________ μm

(2)

(Total 3 marks)

X 210

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Evaluation Did you always show your workings clearly?

Did you always get the conversions between units right?

Did you make accurate measurements

from diagrams?

Did you forget steps in calculations?

Did you use the wrong equation to answer a question?

Did you make notes/annotate the question?

What could you do to improve?

Watch videos on calculations?

Do more practice questions?

How and when will you do this?

Always / Sometimes / Never






Microscope calculations - MissHaynes-Science

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