The cell is the smallest unit of life and makes up all living things. Some living things, like amoebae, are single-cell organisms, while others, such as humans, contain trillions of cells. Compare the characteristics of prokaryotic and eukaryotic cells, and contrast their structure and function in this tutorial focusing on cells and genetics.
Cells are the basic building blocks of all living things. Living things can be made up of a single cell or millions of them. Inside each organism, cells are the smallest unit of life. Each cell has an outer covering called a cell membrane, and internal structures that allow them to grow, use energy, produce new cells, and some cells can even move on their own.
Two different types of cells can be found in organisms.
Prokaryote cells are usually smaller and simpler than eukaryotic cells. Bacteria are an example of prokaryote cells.
Eukaryotic cells contain a nucleus that protects the genetic material of the cell. If the cell is a house, the genetic material found in a cell, called DNA, are like the blueprints. The nucleus is like a bank vault protecting a set of blueprints for a house. In much the same way that humans have organs like a heart and lungs, eukaryotic cells have organelles. Organelles provide a giant list of functions - things like removing waste from the cell, storing water, producing energy, and building tiny structures.