منابع مشابه
Calycanthus chinensis: The Chinese Sweetshrub
are oppositely arranged with short petioles and are glossy green with a touch of roughness on the upper surface. In the Boston area its nodding flowers appear in mid to late spring. Appearances notwithstanding, the sepals and petals are not differentiated (therefore termed tepals): the outer tepals are a silky white with a tinge of pink and a diameter of two to three inches, while the inner tep...
متن کاملChromosome Behavior in Fertile Triploid Aster Hybrids.
HE sterility of triploids and other unbalanced polyploids is generally conT ceded to be a consequence of irregularities in the distribution of univalents and multivalents at meiosis. Occasional viable gametes are produced, however, because of nonrandom orientation and segregation of chromosome associations. Thus, SATINA and BLAKESLEE (1937a, b) found a higher frequency of n and 2n chromosome nu...
متن کاملChromosome Behavior and Nuclear Development in Tradescantia.
COMPARISON of microsporogenesis and microspore development A in a triploid Tradescantia has shown significant deviations from the normal diploid behavior. Occasional dicentric chromatids a t meiosis are found in diploid Tradescantias, but inversion crossovers in the triploid are much more frequent. An analysis of microspore development in a triploid Tradescantia shows that chromosome number has...
متن کاملChromosome Behavior in a Genus Cross.
Crosses between different genera of plants are rare and a satisfactory cytological study of such hybrids has never been made. A comparison of chromosome behavior in genus and species crosses is of interest in connection with a comparison of genetic and taxonomic relationships. A cytological analysis should also show the reason why crosses of genera are almost completely or quite sterile and whe...
متن کاملX-chromosome dosage affects male sexual behavior.
Sex differences in the brain and behavior are primarily attributed to dichotomous androgen exposure between males and females during neonatal development, as well as adult responses to gonadal hormones. Here we tested an alternative hypothesis and asked if sex chromosome complement influences male copulatory behavior, a standard behavior for studies of sexual differentiation. We used two mouse ...
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ژورنال
عنوان ژورنال: Journal of the Arnold Arboretum.
سال: 1933
ISSN: 0004-2625
DOI: 10.5962/bhl.part.9958