ascus

[ as-kuhs ]

noun,plural as·ci [as-ahy, -kahy, -kee]. /ˈæs aɪ, -kaɪ, -ki/. Mycology.
  1. the sac in ascomycetes in which the sexual spores are formed.

Origin of ascus

1
1820–30; <New Latin <Greek askós bag, sac

Words Nearby ascus

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use ascus in a sentence

  • The yellow spores are very minute, each ascus containing eight of them, and they are divided by a transverse partition or septum.

  • This operculum may be the more readily seen when the ascus is coloured by a drop of tincture of iodine.

    Fungi: Their Nature and Uses | Mordecai Cubitt Cooke
  • Each ascus contains a definite number of sporidia, which are sometimes coloured.

    Fungi: Their Nature and Uses | Mordecai Cubitt Cooke
  • The sporidia are usually eight in each ascus, either arranged in single or double rows, or irregularly grouped together.

    Fungi: Their Nature and Uses | Mordecai Cubitt Cooke
  • Other species contain linear sporidia, which are often the length of the ascus, and may either be simple or septate.

    Fungi: Their Nature and Uses | Mordecai Cubitt Cooke

British Dictionary definitions for ascus

ascus

/ (ˈæskəs) /


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

Origin of ascus

1
C19: from New Latin, from Greek askos bag

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for ascus

ascus

[ ăskəs ]


Plural asci (ăsī′, -kī′)
  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.

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