Biology 1 Biomed — 5-topic bundle

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Biology studies life at many different scales, and it's essential to understand how these scales are organized. This organization is often called the hierarchy of biological organization. It moves from the very small and non-living up to the very large and complex living systems.

Cell theory is one of the foundational principles in biology. It states three main things:
1. All living organisms are composed of one or more cells.
2. The cell is the basic unit of structure and organization in organisms.
3. All cells arise from pre-existing cells.

These points highlight that cells are the universal building blocks of life and don't spontaneously appear.

Now, why are cells typically so small? It all comes down to the surface area-to-volume ratio (SA:V).