Now that we've learned that all living things are built from different combinations of four macromolecules, we put those macromolecules together to create structures. This begins our journey through biology starting with the smallest living thing, a cell. A group of cells build tissues (like connective tissue), layers and groups of tissues build organs (like the heart), a set of organs working together form organ systems (like the digestive system), and many organ systems functioning together create an organism (like a human being). This structural ladder of organization begins with a cell. Cells are made of compartments that are extremely small and are called organelles, which is a Latin term and means organ. In this unit you will learn about cell organelles, types of cells, and how cells maintain homeostasis so that an organism can thrive.

Fibrin Network of a blood clot

 More information on cell organelles, types of cells, and homeostasis (diffusion, osmosis, pH)