megaspore

[ meg-uh-spawr, -spohr ]

nounBotany.
  1. the larger of the two kinds of spores characteristically produced by seed plants and a few fern allies, developing into a female gametophyte.: Compare microspore.

  2. the embryo sac of a flowering plant.

Origin of megaspore

1
First recorded in 1885–90; mega- + spore

Other words from megaspore

  • meg·a·spor·ic [meg-uh-spawr-ik, -spor-], /ˌmɛg əˈspɔr ɪk, -ˈspɒr-/, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use megaspore in a sentence

  • The megaspores are, of course, very much larger than the microspores.

    How to Know the Ferns | S. Leonard Bastin
  • The germination of the megaspores is started in the sporangium; at a certain point in their development they are shed.

    How to Know the Ferns | S. Leonard Bastin
  • The number of microspores produced is very large, but only four megaspores are borne in each megasporangium.

    How to Know the Ferns | S. Leonard Bastin
  • The megaspores bear hooks, and in this way the two processes become attached.

    How to Know the Ferns | S. Leonard Bastin

British Dictionary definitions for megaspore

megaspore

/ (ˈmɛɡəˌspɔː) /


noun
  1. Also called: macrospore the larger of the two types of spore produced by some spore-bearing plants, which develops into the female gametophyte: Compare microspore (def. 1)

  2. the cell in flowering plants that gives rise to the embryo sac

Derived forms of megaspore

  • megasporic, adjective

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 megaspore

megaspore

[ mĕgə-spôr ]


  1. One of the two types of haploid spores produced by a heterosporous plant. Megaspores develop into female gametophytes and are usually larger than microspores.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.