a type of microscope that uses visible light and a system of lenses to generate magnified images of small objects

making small objects appear larger in order to see more detail

the minimum distance at which two distinct points of a specimen can still be seen

a type of microscope that uses a beam of electrons instead of light. Electron microscopes have a higher magnification and resolving power than light microscopes

Electron microscopy, and the size and scale of cells

Combined science

Classifying organisms as eukaryotic or prokaryotic

Classification into kingdoms and domains: sub-cellular evidence

Classification and reclassification: genetic evidence

Pupils learned that random genetic mutation is a source of heritable variation, and that evolution occurs through the natural selection of genetic variants linked to advantageous phenotypes.

This unit explores the impact of biology developments on classification systems, highlighting how electron microscopy enhances understanding of sub-cellular structures. It covers eukaryotic and prokaryotic cells, quantitative skills, unit conversions, and the evolution of scientific methods.

Classification in modern biology

Which type of microscope uses electrons to view specimens in 3D?

the distance at which two distinct points of a specimen can still be seen

In microscopy, what does the term 'resolution' refer to?

Which microscope would be most suitable for observing detailed structures within a cell, such as chloroplasts?

A typical human hair has a diameter of approximately 60 micrometres (µm). What is its diameter in nanometres?

The nucleus of a cell measures 5 micrometres (µm) in diameter. In an image, the nucleus appears as 20 millimetres. What is the magnification of the nucleus in the image?

A plant cell has a length of 20 µm, while a bacterium measures 2 µm in length. How many times longer is the plant cell compared to the bacterium?

What is the term for the most basic units of living organisms?

In which type of cell is genetic material typically **not** enclosed within a membrane-bound nucleus?

Which of the following is present in both prokaryotic and eukaryotic cells?

What is the main purpose of a microscope?

Part of an atom that carries a negative charge and orbits the nucleus.

Part of an atom that carries a positive charge and is found in the nucleus.

Part of an atom that carries no overall charge and is found in the nucleus.

Part of an atom where most of the mass of the atom is found.

Electron microscopy, and the size and scale of cells

Lesson outcome