(a)

A student made a drawing of one Escherichia coli bacterium. Fig. 1.2 shows the student's drawing.

Fig. 1.2

The actual length of the bacterial cell is $2 \mu \mathrm{~m}$ .

[ 1 ]

(i)

Convert the actual length of the cell to millimetres. mm [1]

(ii)

State the other information that the student needs in order to calculate the magnification of the drawing in Fig. 1.2.

[ 1 ]

(a)

Fig. 1.3 is a photomicrograph of Vibrio cholerae, the bacterium that causes cholera.

Fig. 1.3

[ 2 ]

(i)

Write the formula that would be used to calculate the actual length of the bacterium (not including the flagellum) in Fig. 1.3.

[ 1 ]

(ii)

The actual length of the bacterium shown in Fig. 1.3 is 0.0026 mm .
Convert this value to micrometres $(\mu \mathrm{m})$ .
.
$\mu \mathrm{m}$

[ 1 ]

[Maximum number: 1]

Fig. 1.1 shows a spongy mesophyll cell from the leaf of a plant. The arrows show the net direction of movement of carbon dioxide molecules during daylight.

Fig. 1.1

(a)

The scale bar in Fig. 1.1 represents 0.01 mm .

Convert 0.01 mm to micrometres. $\mu \mathrm{m}$

[ 1 ]

[Maximum number: 1]

Phytoplankton consist of many species of single-celled and many-celled algae.

(a)

A student investigated the species composition of the phytoplankton in a lake.
Fig. 1.1 shows some of the phytoplankton collected by the student.

Fig. 1.1

The actual length of alga X is 0.19 mm .

Convert the actual length of alga X to micrometres. $\mu \mathrm{m}$

[ 1 ]

[Maximum number: 1]

The diagram shows a mitochondrion. The scale bar shows the actual size of the mitochondrion.

The diagram is 70 mm long.
What is the magnification of the diagram?

A

$\times 0.0007$

B

$\times 70$

C

$\times 7000$

D

$\times 70000$

[Maximum number: 1]

The image shows a pollen grain from a grass plant.

The image has a length of 60 mm .

The actual length of the pollen grain is $500 \mu \mathrm{~m}$ .

What is the magnification of the pollen grain?

A

$\times 0.12$

B

$\times 30$

C

$\times 120$

D

$\times 30000$

[Maximum number: 1]

The diagram shows an epidermal cell from an onion plant.
The distance between X and Y on the diagram is 60 mm .
The actual length of the cell between X and Y is $150 \mu \mathrm{~m}$ .

What is the magnification of the cell?

A

$\times 40$

B

$\times 250$

C

$\times 400$

D

$\times 2500$

[Maximum number: 1]

A student draws a red blood cell.

The diameter of the red blood cell they draw is 20 mm .

The actual diameter of the red blood cell is 0.008 mm .

What is the magnification of the student's drawing?

A

$\times 0.0004$

B

$\times 0.16$

C

$\times 250$

D

$\times 2500$

[Maximum number: 1]

The diagram shows a magnified image of a human liver cell with a mitochondrion labelled. The actual size of the liver cell is $20 \mu \mathrm{~m}$ .

The image size of the liver cell is 40 mm and the image size of the mitochondrion is 4 mm .

What is the actual size of the mitochondrion shown in the diagram?

A

$0.002 \mathrm{~mm}$

B

0.02 mm

C

$0.2 \mathrm{~mm}$

D

2 mm

[Maximum number: 1]

The diagram shows a pollen grain of a rice plant. The size of the image is 40 mm

The actual length of the pollen grain is $40 \mu \mathrm{~m}$ .
By how many times has the diagram been magnified?

A

$\times 1$

B

$\times 10$

C

$\times 100$

D

$\times 1000$