| 单词 | prothallial cell |
| 释义 | > as lemmasprothallial cell prothallial cell n. (in gymnosperms and certain pteridophytes) the smaller of two cells formed by the first asymmetric division of the microspore, sometimes undergoing further division and representing the vegetative tissue of the gametophyte. ΚΠ 1897 Bot. Gaz. 23 428 To suggest that the small cell is a prothallial cell, homologous with the single prothallial cell of heterosporous pteridophytes. 1965 P. Bell & D. Coombe tr. Strasburger's Textbk. Bot. (new ed.) 593 In the originally unicellular microspore (pollen grain) [of Pinus] one or two (or sometimes more) small cells are formed at a particular spot just inside the wall; these prothallial cells often degenerate after a time. 2004 Developm. Biol. 269 320/2 The asymmetric divisions that occur during gametophyte development produce a prothallial cell, six sterile jacket cells, and two spermatogenous initials. < as lemmas |
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