megaspore

American  

[meg-uh-spawr, -spohr] / ˈmɛg əˌspɔr, -ˌspoʊr /

noun

Botany.

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

2. the embryo sac of a flowering plant.

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megaspore British  

/ 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

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

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megaspore Scientific  

/ mĕg′ə-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.

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Other Word Forms

• megasporic adjective

Etymology

Origin of megaspore

First recorded in 1885–90; mega- + spore

Example Sentences

Other fossilized finds include a pinecone-like structure with megaspores and some fossilized tree trunks used to estimate the height of the trees, Wang noted.

From Fox News

The tissue at the apex of the megaspore grows slightly above the level of the archegonia, so that the latter come to lie in a shallow depression.

From Project Gutenberg

For an account of the further development of the megaspore, and the formation of the egg-cell, from which after fertilization is formed the embryo, see Gymnosperms and Angiosperms.

From Project Gutenberg

In both forms cysts containing megaspores and megasporozoites, and others containing microspores and microsporozoites are found, considered as representing sexual differentiation thrown back to the very earliest stages of the life-cycle.

From Project Gutenberg

The behaviour of the chromosomes in meiosis or reduction division both in the pollen mother-cells and in the megaspore mother-cells which give rise to the so-called embryo-sac are fully described by Gates.

From Project Gutenberg