# Resource 4: Magnification exercise

Teacher resource for planning or adapting to use with pupils

## Magnification exercise

1

One of the plant cells in the photograph really measures about 0.01 mm x 0.07 mm. Draw it in your book so its shape and proportions are nearly the same as in the picture.

Calculate magnification of the cell in this way:

Length of cell in drawing ÷ width of real cell = X ______

Mean magnification = X _________

2

Draw an animal cell that is nearly round in shape.

Measure the diameter of your drawing.

Assume this cell is really 0.02 mm in diameter.

Calculate the magnification and show it on your drawing.

3

Draw a line, 10 mm long.

How many of the animal cells could fit on this line side to side?

How many of the plant cells could fit lengthwise on this line side to side?

4

A person’s stride length is about 1 metre.

If you were magnified by the same amount as your drawing of an animal cell, how far could you go in one stride?

5

Measure the length of a small animal such as an ant.

If its skin cells are 0.02 mm long. How many are there along the length of the animal?

6

Write your own question that helps you to understand the size of a cell.

Why does it help you to get a better understanding of this?

See if your neighbour or the rest of the class can work out the answer.

Resource 3: Working with onion cells

Resource 5: Assessing models