Cellular & Molecular Biology

1.2 Organization of the Human Body

The human body can be divided into a hierarchy of organization. This concept is what we will spend the next two semesters in both biology and chemistry to understand. The hierarchical organization is as follows:

• Atom
• Molecules
• Cells
• Tissues
• Organ
• Organ System
• Organism

In chemistry we will study the chemical level (atoms and molecules) in detail. In this course we will spend the semester studying the chemical, cellular and tissue levels. Next semester in Introduction to Human Anatomy and Physiology we will look more closely at the organ, organ system and organismal levels.

Matching Activity

1) Fill in the following diagram of the organ, organ system and organismal levels:

Tissue Level: Tissues consist of similar types of cells.

Organ Level: Organs are made up of different types of tissues.

Organ Systems Level: Organ Systems consist of different organs that work together closely.

Chemical Level: Atoms combine to form molecules.

Cellular Level: Cells are made up of molecules.

Organismal Level: Human organisms are made up of many organ systems.

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