Explore Cells

As cells grow, they get bigger in volume. What happens to the nucleus as the cell grows? Move the slider below to see how a yeast cell and its nucleus changes as the cell grows over time.

Mutations happen when changes are made to the DNA blueprint that controls how a cell looks and behaves. Most mutations have little or no impact on the cell. But sometimes a mutation gives the cell an extra benefit or is harmful to the cell (such as cancer).

Scientists search for mutant cells with certain altered characteristics to learn more about how processes within the cell normally function. For example, mutant cells have been discovered that are much larger and smaller than normal cells. Studying such mutants has offered clues about how cells control their size.

Below are examples of a normal cell and some mutant cells with different cell sizes and shapes. In these examples, even though the cells and nuclei are of very different sizes, the NC ratio remains the same. Such observations have led scientists to discover that changes in cell size and shape often do not impact the NC ratio.

Click on the icons below to see the normal and mutated yeast cells.

Cancer is a disease that comes from harmful mutations in cells. Cancerous cells can no longer function correctly and lose control of their size and shape.

Cancerous cells look different from regular cells in a number of ways. In certain types of cancers, the cell size, nucleus size, and shape begin to change. As time goes on, these changes become more extreme.

Doctors describe how advanced a cancer is in grades. The higher the grade number, the more abnormal the cells are. Cancers with a higher grade are more difficult to treat, and the cells of these cancers are more likely to spread to other parts of the body. Because of this, it's important for doctors to be able to identify cancer cells early, while the disease is easier to treat.

One of the ways that scientists can identify the grade of cancer cells is simply by looking at them under a microscope and measuring their NC ratio. In this example (from cervical cancer cells), the increases in the NC ratio indicate that the grade of the cancer is more advanced.

Move the slider below to see the development of a cell from normal to more advanced cancer grade. Observe how the cell size, size of the nucleus, and NC ratio change.