What does megaspore mean?
A megaspore is the larger, female-associated spore produced by certain plants, especially seed plants and some ferns. In flowering plants, a megaspore forms within the ovule and develops into the female gametophyte, commonly called the embryo sac, which contains the egg cell. The term is paired with microspore, the smaller spore that develops into a male gametophyte. Megaspores are produced through meiosis from a megaspore mother cell, although only one megaspore may remain functional in many flowering plants. The word is most often encountered in plant biology, botany, and discussions of reproduction in seed plants. Its size distinction is useful, but the biological distinction is more precise: megaspore and microspore refer to the reproductive lineages into which the spores develop, not merely to their physical dimensions.
nounA large spore produced by certain plants, especially seed plants and some ferns, that develops into a female gametophyte. In flowering plants, the megaspore remains within the ovule and develops into the embryo sac.
- A large, female-producing spore in heterosporous plants.
- The large spore in seed plants that develops into the female gametophyte, including the embryo sac in flowering plants.
"The megaspore develops into the female gametophyte, which contains the egg cell."
"In an ovule, the megaspore mother cell undergoes meiosis to produce megaspores."
"The surviving functional megaspore develops into the embryo sac in many flowering plants."
The usual plural of megaspore.
"Several megaspores are produced, but usually only one remains functional."
In a flowering plant, the megaspore is a microscopic world in waiting: it develops into the embryo sac, the structure that eventually houses the egg cell.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of megaspore
The word combines the Greek combining form mega-, meaning large, with the botanical term spore, from Greek spora, meaning seed or sowing. In modern botanical terminology, the prefix distinguishes the larger or female-producing spore from the microspore, the smaller or male-producing spore. Related terms include microspore, heterospore, and isospore, all built on the same spore root.
Related word forms
How megaspore is actually used
Megaspore is primarily a botanical term. It is used especially for the larger of the two kinds of spores in heterosporous plants and contrasts with microspore; in flowering plants, it is commonly described as developing into the embryo sac.
Easily confused with megaspore
A megaspore is a large spore that develops into a female gametophyte, whereas a microspore is a small spore that develops into a male gametophyte.