It’s hard to say which type of human cell is most important because we need most all of them to survive. It is sort of similar to asking which part of a car is most important. Most people would say the engine, but without the bolts securing the engine, the engine wouldn’t be useful. Similarly, for the human body, it is tempting to say the brain cells are most important because they coordinate all of the body’s life functions. However, without the cells that make up your heart, you wouldn’t be able to pump blood throughout your body. Also, without your immune cells to defend against invaders, you wouldn’t last more than a few days. So for a full grown human, there are certainly cells that are more important to keeping a human alive, but ultimately they all play an important part.

Though, if you talk about the entire life of a human, the most important cell would be the fertilized egg cell or “zygote". This is the first cell that that defines a new person, different than their mother or father. The zygote is a “totipotent” cell meaning it can turn into any cell in the human body. The zygote divides every 12-24 hours until you have the tens of trillions of cells in a mature human! This cell is only present in the very beginning of a human’s life though.

Every cell in the human body is very important. Although each individual cell can not do the work of all trillion cells we have, they are important. We have neurons which are cells that transport messages to and from the brain. We have optical cells in our eyes that take in light to see our surroundings. We have cells in our ears that support the hairs that detect sounds. Our skin cells protect us from diseases and other harm.

If you forced me to chose a type of cell that is most important, I would pick our stem cells. These cells live for as long as we are alive. This is different from regular cells that die and are replaced by new ones. Stem cells can make ANY cell in your body. It can be a cell in your tongue, a bone cell, a cell in your eye, or a skin cell. Since this type of cell can make any other type of cell, and lives so long, I'd say it is the most important. That is my opinion - I hope you get other answers to see if we agree or disagree (which is a part of science!).

There is no way to answer this. Each human cell has its use. Many of those uses are needed for the human to live. If forced to pick one, however, it would be the stem-cells: the cells that create all other cells.