Question

What is the different between stem cells and "normal" cells?

Answer 1

There are several differences.

1. Normal cells are specialized and cannot become other types of cells. Like the cells in your eyes cannot become the cells in your brain. Stem cells can change into any type of specialized cells.

2. Normal cells cannot divide forever. Their dna shortens with each division and they eventually die out. Stem cells are called immortal cells because they can divide forever. Their dna doesnt get shorter with each division until it has been changed into a specialized cell.

*Sources Internet

Answer 2

@KittyT both of your points are only partly correct. :-)

1: specialized cells can, in fact, 'become stem cells'. and there's two ways of achieving that: a) in plants, cells can be stimulated to 'undifferentiate', forming callus tissue. b) cancer cells can achieve a state where they exhibit 'induced pluripotency'.

2: The DNA of ALL cells gets shorter which each cycle, both in stem cells and 'normal' cells. BUT: Stem cells are potentially invulnerable. And here's why:

Through each cell division, the DNA that makes up our chromosomes is slightly shortened at the ends. (if you wanna know why, just ask =) )

The ends of our chromosomes are structures called 'telomers'. They are basically DNA repeating the sequence TTAGGG over and over.

Now, normal cells can't do anything about this shortening, and will cease to procreate after a certain amount of cell divisions (called the Hayflick Limit).

But stem cells express a protein called 'telomerase', which works as a primer and can renew the telomeres.

You see now, how a cell can 'become immortal': Just make the telomerase, and you're fine :-) There is, however, a reason for cells being mortal. During every cell cycle, mistakes are made while copying the DNA. By the time the Hayflick Limit is reached, the cell's DNA has mutated in several places and the probability for cancer in this very cell has risen. That's why it has to die.

Answer 3

Thanks @Schleifspur for correct me and give me some knowledge about cells. Thanks to that! It's really helpful. :)

Answer 4

Hello @shannon96 Thank you for your medal. I really appreciate it! I really happy to help you! Bye :)