A type of microscope that uses visible light and lenses to generate magnified images of small objects.

A type of microscope that uses a beam of electrons instead of light to magnify objects.

Making small objects appear larger in order to see more detail.

The minimum distance apart that two points of a specimen can be and still be clearly seen as separate from one another using a microscope.

A way of writing down very large or very small numbers easily; e.g. 1000 = 10³.

Electron microscopy, and the size and scale of cells: including standard form

Biology

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?

making small objects appear larger in order to see more detail

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?

A mitochondrion has a length of 2 micrometres (µm). In a microscopic image, the mitochondrion is represented as 0.5 centimetres. What is the magnification of the mitochondrion in the image?

Given an image size of a red blood cell measuring 2 × 10⁻² mm and a magnification factor of 1000x, determine the real size of the red blood cell. Give your answer in metres (m) using standard form.

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 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: including standard form

Lesson outcome