منابع مشابه
Fine Structure of Chromosomes
Electron micrographs of staminate hair cells of Tradescantia reflexa indicate that early prophase chromosomes are composed of a number of helically arranged chromonemata. Favorable preparations reveal as many as 64 identifiable subsidiary strands, assumedly arranged as intertwined pairs to form a hierarchy of pairs of pairs. The helices of the smallest discernible units have a diameter of about...
متن کاملthe underlying structure of language proficiency and the proficiency level
هدف از انجام این تخقیق بررسی رابطه احتمالی بین سطح مهارت زبان خارجی (foreign language proficiency) و ساختار مهارت زبان خارجی بود. تعداد 314 زبان آموز مونث و مذکر که عمدتا دانشجویان رشته های زبان انگلیسی در سطوح کارشناسی و کارشناسی ارشد بودند در این تحقیق شرکت کردند. از لحاظ سطح مهارت زبان خارجی شرکت کنندگان بسیار با هم متفاوت بودند، (75 نفر سطح پیشرفته، 113 نفر سطح متوسط، 126 سطح مقدماتی). کلا ...
15 صفحه اولCytoplasmic Fine Structure of Sciara Salivary Glands
Cells from the anterior segment of the salivary glands of Sciara coprophila were found to synthesize and secrete into the gland lumen three morphologically distinct types of granule: 1) A large, electron-lucid granule, up to 1 micro in diameter, staining only faintly with pH 2 fast green and the PAS reaction; 2) an ellipsoid granule of moderate density, strongly fast green and PAS positive; and...
متن کاملFine structure of the cytoplasm in salivary glands of Simulium.
The salivary glands of 3rd or 4th instar larvae of Simulium niditifrons are about 5 mm long and up to 400 fi wide. They have a capacious lumen which is normally filled with secretion. The apical (luminal) plasmalemma of the gland cells is thrown into numerous microvilli. The basal plasmalemma is usually straight but is infolded in places. The infoldings may be complex near to cell junctions. Th...
متن کاملStructure and Arrangement of Salivary Gland Chromosomes in Drosophila Species.
goes a profound change in electronic structure on attachment to hemoglobin. The magnetic susceptibility of hemoglobin itself (ferrohemoglobin) corresponds to an effective magnetic moment of 5.46 Bohr magnetons per heme, calculated for independent hemes. This shows the presence of four unpaired electrons per heme, and indicates that the heme-heme interaction tends to stabilize to some extent the...
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ژورنال
عنوان ژورنال: CYTOLOGIA
سال: 1951
ISSN: 0011-4545,1348-7019
DOI: 10.1508/cytologia.16.233