bitetrad

plural bitetrads

1. biologyA group or arrangement consisting of two tetrads.

   These works revealed that Mimosa pollen grains canbe grouped into tetrads, bitetrads (eight grains) or polyads (12 or 16 grains).

   2013, JULIANA SANTOS-SILVA, MARCELO FRAGOMENI SIMON, ANA MARIAGOULART DE AZEVEDO TOZZI, “Pollen diversity and its phylogenetic implications in Mimosa ser.Leiocarpae Benth. (Leguminosae, Mimosoideae)”, in Grana, volume 52, number 1, page 16

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   Bitetrads are found in Piptadeniopsis (Fig. 10), Micro-lobius (Fig. 9) and in any species of Mimosa(Fig. 4) and Piptadenia, but tetrads and/or polyads are present in the same taxa too.

   2002, MARTA A. CACCAVARI, “Pollen morphology and structure of Tropical and SubtropicalAmerican genera of the Piptadenia-group (Leguminosae:Mimosoideae)”, in Grana, volume 41, number 3, page 131

2. chemistryA structural unit composed of two tetrads within a crystal lattice or molecular structure.

   To achieve this, one has to pay a relatively high price, namely to increase the number of degrees of freedom, replacing the tetrad field by the bitetrad field.

   2002, PIOTR GODLEWSKI, “BITETRAD AS GEOMETRODYNAMICAL VARIABLE FOR GL(2, C)-INVARIANT MODELS OF MUTUALLY INTERACTING GRAVITATIONAL AND BISPINOR FIELDS”, in REPORTS ON MATHEMATICAL PHYSICS, volume Vol. 49, number 1

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   Two tetrads are also assumed to join base to base producing the bitetrad, and from these two forms the tetrad and the bitetrad, all the atoms and molecules of our planet are supposed to be produced.

   1870 August 11, Nature: A Weekly Illustrated Journal of Science, volume II, New York: MacMillan and Co, page 295

   Single tetrads, whenever they ar not permitted to cohere in larget numbers, will in every case cohere as bitetrads. Are we, then, to look for the bitetrad among chemical elements?

   1870, John G. Macvicar, LL.D., D.D., A Sketch of a Philosophy, Part III. The Chemestry of Natural Substances, London: Williams & Norgate, page 29