queen bee

noun3

1. •
   A reproductive female (especially the only one) in a colony of bees.

   • It is generally believed that the queen bee mates only once in her lifetime. — 1947
2. •
   (informal) The most important or dominant woman in an organization or situation.

   • She muttered to her mother, “There's that obnoxious redhead who thought she was the Queen Bee last year when she was a senior!” — 2003
3. •
   (figurative) A stem cell.