CIE A Level Biology

Topic Questions

Syllabus Edition

First teaching 2020

Last exams 2024

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1.1 The Microscope in Cell Studies

11 mark

The statements below are about light microscopes. 

1

As the magnification increases the resolution decreases.

2

The resolution of a light microscope is limited by the wavelength of light.

3

To calculate the magnification of a light microscope the eyepiece lens and objective lens magnifications are added together.

4

The scale on a stage micrometer is resolved more clearly than an eyepiece graticule.

Which statements are correct?

  • 1 and 2

  • 1 and 4

  • 2 and 3

  • 3 and 4

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21 mark

Which row compares correctly the magnification and resolution of an electron microscope with a light microscope?

  magnification resolution
A lower higher
B higher lower
C higher higher
D lower lower

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31 mark

Approximately at which magnification would a light microscope not be suitable because the resolution becomes too low?

  • cross times100

  • cross times200

  • x 400

  • cross times1500

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41 mark

Compared to a light microscope the electron microscope has a higher resolution.

Which of the following is a result of a higher resolution?

  • The ability to see mRNA in all cells.

  • The ability to see the nucleus in eukaryotes.

  • The ability to produce larger images of cells.

  • The ability to see cristae in mitochondria.

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51 mark

Cells can be measured using eyepiece graticules and stage micrometers.

Which of the following correctly describes why a stage micrometer is calibrated?

  • The eyepiece graticule is magnified by the objective lens.

  • An eyepiece graticule can be used to make measurements.

  • An eyepiece graticule magnifies the specimen.

  • An eyepiece graticule makes comparisons.

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61 mark

The list of organelles below are viewed by a microscope with resolution of 200 nm. 

Which organelles would not be resolved by this microscope?

  • mitochondria

  • lysosomes

  • ribosomes

  • chloroplasts

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71 mark

Which of the following would restrict the resolution of the light microscope?

  • The low magnification produced by glass.

  • The wavelengths of visible light.

  • The low light intensity of microscope lamps.

  • The inability to cut very thin sections.

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81 mark

Which of the options correctly describe the resolution, in nanometres, of an electron microscope and of a light microscope?

  electron microscope light microscope
A 5.0 20
B 5.0 200
C 0.5 20
D 0.5 200

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91 mark

A lysosome has a diameter of 0.4 µm. What is the diameter in nm?

  • 4nm

  • 40nm

  • 400nm

  • 4000nm

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101 mark

What is meant by resolution in light microscopy?

  • The size of the smallest object that can be seen.

  • Twice the wavelength of the light used to illuminate the specimen.

  • The shortest distance between two objects that can be seen as separate.

  • The product of the magnifications of the eyepiece and the objective lens.

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11 mark

The actual length of a cell structure is 6 µm.

A student was asked to write an equation that could be used to calculate the magnification of an electron micrograph of this cell structure. The student used the letters q to u in their equation.

q = The length of the cell structure in the image in cm

r = The length of the cell structure in the image in mm

s = 1000

t1 over 6

u = 6

Which of the following would be the correct equation to calculate the magnification?

  • q over s cross times u

  • q cross times s cross times t

  • fraction numerator r cross times s over denominator u end fraction

  • r over s cross times u

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21 mark

A stage micrometer with small divisions of 0.1 mm was used to calibrate a graticule. This is shown in the diagram below.

qn-22

A slide of a plant cell was placed on the stage in place of the stage micrometer. 

 What is the width of the chloroplast below?

qn23

  • 100 µm

  • 50 µm

  • 10 µm

  • 0.5 mm

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31 mark

Cells can vary considerably in their diameter.

Typical diameters of cells are:

  • Eukaryotic cells, such as a white blood cell          1.5 x 101 µm
  • Prokaryotic cells, such as Streptococcus              7.5 x 102 nm

Use these measurements to find the maximum number of each cell that could fit along a 1 cm line.

  Number of white blood cells Number of Streptococcus cells
A 6.7 x 100 1.3  x 102
B 6.7 x 101 1.3  x 103
C 6.7 x 102 1.3  x 104
D 6.7 x 103 1.3  x 105

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41 mark

A light microscope with an eyepiece lens of x5 and an objective lens of x8 was used to draw the diagram of a transverse section through a leaf, as shown below.

qn24

The actual length of the leaf is 7.5 mm. What is the magnification of the diagram?

  • x40

  • x20

  • x8

  • x5

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51 mark

The diagram below is viewed through an eyepiece with a graticule showing the stage micrometer below. The stage micrometer has divisions 0.1 mm apart.

qn-7

The eyepiece is then used to examine a blood smear.

How many of the graticule divisions will cover the diameter of a white cell of 12.5 µm?

  • 1

  • 4

  • 5

  • 10

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61 mark

A light microscope is used to observe a specimen under green light with a wavelength of 510 nm.

If the same specimen, with all other conditions kept constant, is viewed under red light with a wavelength of 650 nm, what effect would this have on the magnification and resolution of the microscope?

  magnification resolution
A stays the same increased
B stays the same decreased
C increased decreased
D decreased increased

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71 mark

The diagram below shows a view through a microscope eyepiece with a graticule scale and a stage micrometer using a magnification of x400.

qn28

Using the magnification of x400, a chloroplast was measured to be 4 eyepiece graticule divisions in length.

How long is the chloroplast?

  • 4.0 x 102 µm

  • 2.5 x 10-1 µm

  • 2.5 x 10-2 µm

  • 1.0 x 101 µm

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81 mark

The diagram below shows a view through a microscope eyepiece with a graticule scale and a stage micrometer, with divisions 0.1 mm apart.

qn29

What is the area of the field of view at this magnification? (straight pi = 3.14)

  • straight pi x 250 x 250 = 2.0 x 105 µm2

  • straight pi x 50 x 50 = 7.9 x 103 µm2

  • straight pi x 12.5 x 12.5 = 4.9 x 102 µm2

  • straight pi x 125 x 125 = 4.9 x 104 µm2

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91 mark

A student was using an eyepiece graticule with 100 small divisions. The stage micrometer they were using had a scale with 50 divisions, each of them 0.04 mm apart.

Using a x40 objective lens, the whole length of the stage micrometer lined up with 15 divisions of the eyepiece graticule.

What is the length of the 100 division scale of the eyepiece graticule at this magnification?

  • 750 µm

  • 75 µm

  • 13 mm

  • 1.3 mm

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11 mark

Which of the following is not a correct description of a light microscope or an electron microscope?

  • An electron microscope can resolve specimens as small as 0.5 nm in diameter.

  • A light microscope has a maximum resolution of 0.2 µm.

  • An electron microscope has a maximum resolution of 0.05 nm.

  • A light microscope can resolve specimens as small as 200 nm in diameter.

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21 mark

A prokaryotic cell is magnified 50 000 times by an electron microscope, it has a diameter of 1 µm.

What is the diameter of the cell in an electron micrograph?

  • 5 x 10 to the power of 0 mm

  • 5 cross times10-1  mm

  • 5 x 102 mm

  • 5 x 101 mm

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31 mark

The electron micrograph below shows the organelles in a leaf cell.

A ruler has been added to show the size of the image alongside the scale bar which shows the distance that represents 5 µm.

em-with-ruler

What is the magnification of this image?

  • x7000

  • ×3570

  • x2800

  • x280

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4
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1 mark

The electron micrograph below shows a root vascular system.

The magnification of the image is x200 and Y has a diameter of 1 cm when measured using a ruler.

screenshot-2023-04-28-094858

What is the diameter of the cell labelled Y?

  • 100 µm

  • 50 µm

  • 10 µm

  • 5 µm

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51 mark

To view the actual width of a transverse section of a xylem vessel with a x40 lens, which steps are needed?

1

Measure the width of the xylem vessel using an eyepiece graticule.

2

Calibrate the eyepiece graticule using a stage micrometer on x10 objective lens.

3

Convert from mm to µm by multiplying by 10-3

4

Multiply the number of eyepiece graticule units by the calibration of the eyepiece graticule.

  • 1 and 2

  • 2 and 3

  • 1 and 3

  • 1 and 4

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61 mark

The electron micrograph of the plant cell has a 2 cm scale line labelled 5 µm.

ma-16

What is the magnification?

  • 5 x 103

  • 4 x 103

  • 2 x 103

  • 1 x 103

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71 mark

Erythrocytes (red blood cells) have a diameter of 7000 nm. Pancreatic cells have a diameter of 35 µm.

Which of these statements is correct about the relative sizes of these cells?

  • The erythrocytes are 5 times smaller.

  • The erythrocytes are 50 times smaller.

  • The erythrocytes are 5 times larger.

  • The erythrocytes are 50 times larger.

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81 mark

The table shows some approximate units for measuring the diameters of alveoli, white blood cells and the width of cell walls.

Which of the rows show the correct units for these structures?

  Diameters of alveoli Diameters of white blood cells Width of cell walls
A mm µm µm
B mm µm nm
C µm nm µm
D µm µm nm

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91 mark

The following statements describe slide preparation. 

Which one would refer to a wet mount preparation of a slide for observation with a light microscope? 

  • Methylene blue is added to the specimen.

  • A coverslip is placed on the specimen.

  • The low power lens is above the object on the stage.

  • A drop of water is added to the specimen.

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101 mark

The following statements describe drawing a scientific drawing.

Which is not a correct statement about drawing scientifically?

  • The magnification should be stated.

  • Label lines should have arrowheads.

  • White unlined paper should be used.

  • Lines should be drawn with a smooth continuous line.

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