Biology Topic Practice

Size, Scale & Units

Cells are measured in tiny units, often requiring standard form or conversions between millimetres and micrometres.

How many micrometres are in 1 millimetre?

What is Size, Scale & Units?

"Size and scale in biology refer to the dimensions of biological structures and the units (like micrometres) used to measure them accurately."

Question 1

Which answer best completes the statement? The nucleus contains ____ and controls the cell

Question 2

Why are cultures in school laboratories usually incubated at about 25°C rather than 37°C?

Question 3

Osmosis is the diffusion of water through a:

Question 4

Which answer best completes the statement? The permanent vacuole is filled with ____

Cellular Scale

1 mm = 1,000 µm (micrometres).

1 µm = 1,000 nm (nanometres).

Standard form: Used to write very large or very small numbers (e.g., 2 x 10^-6 m).

Always use the same units when comparing the sizes of different organelle images.

Exam Tip

Practice converting backwards and forwards: 0.05 mm is 50 micrometres.

Want to improve faster?

The fastest way to improve your grade is to practise exam-style questions, identify your gaps, and focus only on what you don't know.

Start practising this topic
Instantly marked • No sign-up