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| Goulart,Rosangela de Carvalho; Marin,José Moacir. |
| Some filamentous fungi present the phenomenon of dimorphism, their morphological structure alterations being capable of inducing metabolism changes. The Aspergillus niger strain 10v10, a producer of citric acid, was submitted to the mutagenic action of ultraviolet irradiation which respectively selects mutants sensitive or resistant to the antifungi agent 5 fluorocytosine (5-FC). 5-FC sensitive mutants presented a morphological alteration to a yeast-like form. The effects of pH changes, addition of salts (KH2PO4, NH4NO3, MgSO4 and MgCl2), the presence of osmotic stabilizers, as well as of calcium chloride, on morphological reversal and acid production were studied. Morphological reversal to the filamentous form was observed only in the presence of CaCl2... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aspergillus niger; 5-fluorocytosine; Yeast-like; Calcium; Acid production; Dimorphism. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822005000300018 |
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| Castillo,Raúl Cueva del. |
| Few theoretical and experimental studies have analyzed the genetic basis of body size dimorphism. Since the evolutionary response to selection depends of the genetic variance in a population it is to be expected that traits under selection would have smaller genetic variance than traits not affected by selection. The evolution of sexual size dimorphism is affected by the genetic correlation between females and males, with the most dimorphic traits showing smaller genetic correlations between the sexes. As result of the differences in the intensity of sexual selection between the sexes, it is expected that the levels of genetic variance would be larger in females than males. I analyzed the genetic additive variance underlying six traits of Acheta... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Acheta domesticus; Body size; Dimorphism; Heritability; Sexual selection. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000500030 |
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| Kakabadze, M.V.. |
| The variability in the dimensions of the shell, and some changes in suture line, sculpture, whorl section and mode of coiling in the late ontogenetic stages, have in some cases no taxonomic significance for the recognition of genera and higher taxa of Cretaceous heteromorph ammonites. In many cases, such phenomena are due to intraspecific variation or variation within a genus. The intrageneric variations of some Cretaceous heteromorphs are discussed in detail in the light of new, rich Colombian material. In relation to these problems in systematics, some questions on the systematics of the superfamily Ancyloceratoidea Gill are considered. |
| Tipo: Article / Letter to the editor |
Palavras-chave: Ammonites; Heteromorphs; Dimorphism; Systematics; Cretaceous; 38.22; 42.73. |
| Ano: 2004 |
URL: http://www.repository.naturalis.nl/record/214457 |
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| Carvalho,Barbara Maichak de; Volpedo,Alejandra Vanina; Fávaro,Luís Fernando. |
| Abstract This study aimed to verify variations in the form of the sagitta otolith of Menticirrhus americanus as to their ontogeny, sex and stage of such structure. Ontogenetically were found significant differences (p < 0.05) for all shape indices (aspect ratios, shape factor, rectangularity, ellipticity, relative surface of sulcus acusticus) and also in the wavelet of the otolith. The CVA presented a 98.6% correct reclassification of the otolith between interval class. Sexual variations were found in the wavelet and in the relative surface of sulcus acusticus index. Between adult females and young females, differences were not detected in the wavelet and rectangularity, but significant differences were found in all other shape indices. The CVA... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dimorphism; Otolith; Shape indices; Stage of life; Wavelet. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0031-10492020000100209 |
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