zona
/ˈzoʊnə/
noun
- A zone or area, especially a distinct region or band on a surface or in the body.
- The doctor explained that the rash was limited to a single zona on his back.
- The microscope revealed a dark zona around the nucleus of the cell.
- In geography class, we learned about the torrid zona near the equator.
- Short for zona pellucida, the thick transparent membrane surrounding a mammalian egg cell.
- The sperm must penetrate the zona to fertilize the egg.
- Scientists studied how enzymes break down the zona during fertilization.
- Damage to the zona can prevent an embryo from implanting in the uterus.