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American Heritage Dictionary - Cite This Source - Share This

zy·go·spore       (zī'gə-spôr', -spōr', zĭg'ə-)  Pronunciation Key  n.   A large multinucleate spore formed by union of similar gametes, as in algae or fungi.

WordNet - Cite This Source - Share This

zygospore

noun

a plant spore formed by two similar sexual cells

The American Heritage Science Dictionary - Cite This Source - Share This

zygospore       (zī'gə-spôr', zĭg'ə-)  Pronunciation Key  A large, multinucleate spore formed by union of isogametes (gametes that are not distinguished by size and structure), as in certain algae or fungi. A zygospore develops thick, resistant walls and enters a period of dormancy before germinating.

Webster's Revised Unabridged Dictionary - Cite This Source - Share This

Zygospore

Spore\, n. [Gr. ? a sowing, seed, from ? to sow. Cf. Sperm.]

1. (Bot.) (a) One of the minute grains in flowerless plants, which are analogous to seeds, as serving to reproduce the species.

Note: Spores are produced differently in the different classes of cryptogamous plants, and as regards their nature are often so unlike that they have only their minuteness in common. The peculiar spores of diatoms (called auxospores) increase in size, and at length acquire a siliceous coating, thus becoming new diatoms of full size. Compare Macrospore, Microspore, O["o]spore, Restingspore, Sph[ae]rospore, Swarmspore, Tetraspore, Zo["o]spore, and Zygospore. (b) An embryo sac or embryonal vesicle in the ovules of flowering plants.

2. (Biol.) (a) A minute grain or germ; a small, round or ovoid body, formed in certain organisms, and by germination giving rise to a new organism; as, the reproductive spores of bacteria, etc. (b) One of the parts formed by fission in certain Protozoa. See Spore formation, belw.

Spore formation. (a) (Biol) A mode of reproduction resembling multitude fission, common among Protozoa, in which the organism breaks up into a number of pieces, or spores, each of which eventually develops into an organism like the parent form. --Balfour. (b) The formation of reproductive cells or spores, as in the growth of bacilli.