| 单词 | testa |
| 释义 | testa noun[C] biologyspecializeduk/ˈtes.tə/us/ˈtes.tə/pluraltestaeinplantswithflowers, a hardlayerthatcoversandprotectsthesurfaceof aseed 外种皮（覆盖和保护种子表面的硬皮）Parts of plants
Examplesoftestatesta Thistestaprobably reduced the rate of water loss and protected the embryo from physical injury. From theCambridge English Corpus In four instances, thetestawas removed from one end of the seed and the fleshy cotyledons eaten from the centre. From theCambridge English Corpus In both species, seeds lacking testae began to soften about day 8, were often attacked by fungus, and had rotted completely by day 10. From theCambridge English Corpus In this work, emphasis is placed on the existence of seed mutants having major alterations in characteristics of thetestaand hormonal response. From theCambridge English Corpus Thetestaepidermis is peculiar in that the outer walls of dry seeds are invaginated, while they bulge outwards in wetted seeds. From theCambridge English Corpus Seeds were considered germinated when the embryo had just ruptured thetesta. From theCambridge English Corpus It is, therefore, tempting to ascribe more rapid completion of germination to an ethyleneinsensitivetestadeveloping in an ethylene-insensitive environment. From theCambridge English Corpus Progress oftestarupture is facilitated by channels underlying the ridges. From theCambridge English Corpus The molecular data presented here are consistent with the anatomical and biochemical differences between the wild-type and the mutant testae. From theCambridge English Corpus The completion of germination was defined as the radicle visibly protruding from thetesta. From theCambridge English Corpus A slow rate of ethylene production was found in these seeds, thetestabeing the source. From theCambridge English Corpus The mutant 20-dpatestadid not stain blue (instead it stained purple), and hypodermal cells were not reticulated (data not shown). From theCambridge English Corpus I suggested a mechanical function of thetesta. From theCambridge English Corpus Small bites had been taken from another seed although there was no evidence that thetestahad first been removed. From theCambridge English Corpus From a small area of the dry seed surface thetestawas removed and 5 mg of flour was scratched from the cotyledons. From theCambridge English Corpus These examples are from corpora and from sources on the web. Any opinions in the examples do not represent the opinion of the Cambridge Dictionary editors or of Cambridge University Press or its licensors. |
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