Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
An ascus is a specialized cell in which spores of ascomycete fungi are formed. It typically contains eight ascospores arranged in a sac-like structure.
5 Must Know Facts For Your Next Test
Asci are characteristic of the Ascomycota phylum of fungi, also known as sac fungi.
Each ascus usually produces exactly eight ascospores through sexual reproduction.
The formation of asci is a key step in the fungal life cycle called meiosis.
Asci can be found within larger fruiting bodies called ascocarps or perithecia.
The release of ascospores from the ascus often involves mechanisms that ensure wide dispersal for colonization.