ascus

American  

[as-kuhs] / ˈæs kəs /

noun

Mycology.

• asci
  plural

1. the sac in ascomycetes in which the sexual spores are formed.

---

ascus British  

/ ˈæskəs /

noun

1. a saclike structure that produces (usually) eight ascospores during sexual reproduction in ascomycetous fungi such as yeasts and mildews

---

ascus Scientific  

/ ăs′kəs /

• asci
  plural

1. A membranous, often club-shaped structure inside which ascospores are formed through sexual reproduction in species of the fungi known as ascomycetes. The ascus is unique to ascomycetes and distinguishes them from other kinds of fungi. Asci are formed when two hyphae that are sexually compatible conjugate. Each ascus typically develops eight ascospores. Asci swell at maturity until they burst, shooting the ascospores into the air.

---

Other Word Forms

Noun Inflected Forms

• asci
  plural

---

Etymology

Origin of ascus

1820–30; < New Latin < Greek askós bag, sac

---

Example Sentences

See Examples For:

ascus asci

A dikaryotic ascus that forms in the ascocarp undergoes plasmogamy, meiosis, and mitosis to form eight ascospores.

From Textbooks ● Jan. 1, 2015

A dikaryotic ascus that forms in the ascocarp undergoes karyogamy, meiosis, and mitosis to form eight ascospores.

From Textbooks ● Jan. 1, 2015

The zygote undergoes meiosis without cell division, resulting in an ascus with four 1n nuclei arranged in a row.

From Textbooks ● Jan. 1, 2015

You can count the eight ascospores in this ascus: The tasty, tasty asci of a Morchella sp.

From Scientific American ● Sep. 5, 2012

The single nucleus divides by three successive divisions to form eight nuclei lying free in the protoplasm of the ascus.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 3 "Frost" to "Fyzabad" by Various

Some asci have elastic rings at their tips that only allow spores out once a set pressured is reached.

From Scientific American ● Sep. 5, 2012

In the diagram above, you can see the asci at various stages in meiosis.

From Scientific American ● Sep. 5, 2012

In ascomycetes that build their asci inside flask-like structures called perithecia or pseudothecia, the asci take turns snaking to the little opening, poking themselves out, and firing.

From Scientific American ● Sep. 5, 2012

You can count the eight ascospores in this ascus: The tasty, tasty asci of a Morchella sp.

From Scientific American ● Sep. 5, 2012

The sporidia are produced in membraneous asci, usually four or eight, or some multiple of that number, in each ascus; Cooke says "rarely four, most commonly eight."

From Student's Hand-book of Mushrooms of America, Edible and Poisonous by Thomas Taylor

Random Word

Spin the wheel and learn a new word!

---