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

The megaspore divides three times to form an eight-cell stage.

From Textbooks • Jan. 1, 2015

In the female cone, megaspore mother cells are present in the megasporangium.

From Textbooks • Jan. 1, 2015

Only the large megaspore survives; it produces the female gametophyte, referred to as the embryo sac.

From Textbooks • Jan. 1, 2015

When the pollen lands on a female scale, a pollen tube grows toward the female gametophyte, which consists of an ovule containing the megaspore.

From Textbooks • Jan. 1, 2015

Embryo-sac, the name given to the megaspore of seed-plants.

From The New Gresham Encyclopedia Volume 4, Part 2: Ebert to Estremadura by Various