Cell diagrams, side by side.

What these cell diagrams have in common

Each cell needs a boundary, genetic information, a means of making proteins and an internal environment where reactions can occur. The diagrams therefore share a plasma membrane, DNA, ribosomes and cytoplasm, even though the organization differs.

The figures are explanatory models at different illustrative scales. Do not compare their drawn widths to infer real cell sizes. They also combine selected structures rather than representing every cell in a group.

Plant, animal and prokaryotic cells compared

The table describes general models. Specialized cells and different organisms introduce exceptions. For example, a root cell need not contain chloroplasts, and a mature mammalian red blood cell lacks a nucleus.

Eukaryotic versus prokaryotic is a different comparison

Plant and animal cells are both eukaryotic. The defining distinction in this introduction is the membrane-bound nucleus, together with the broader organization of internal compartments.

A cell wall does not decide the category: plants and many prokaryotes have walls, while animal cells do not. Likewise, the absence of a nucleus does not mean a prokaryote has no DNA.

• Explore eukaryotic organization
• Explore the bacterial model

Choose a useful diagram for your class

For a first comparison, use a short list: membrane, nucleus or nucleoid, ribosomes and the structures characteristic of the chosen model. Add organelles when the lesson requires their functions.

The individual diagram pages include labeled and unlabeled downloads and parts tables. For a worksheet, use the unlabeled views and ask students to explain one similarity and one difference, rather than only matching names to arrows.

Build a lecture and worksheet sequence →