An electron microscope study of the fine structure of Acremoniella velata

1968 ◽  
Vol 51 (3-4) ◽  
pp. 515-IN13 ◽  
Author(s):  
D. Jones
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Microscope Study ◽  
Electron Microscope Study

An Electron Microscope study of a Small Free-living Amoeba (Hartmanella astronyxis)

1959 ◽  
Vol s3-100 (49) ◽  
pp. 13-15
Author(s):  
K. DEUTSCH ◽  
M. M. SWANN
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Cell Membrane ◽  
Nuclear Membrane ◽  
Layered Structure ◽  
Microscope Study ◽  
Electron Microscope Study ◽  
Honeycomb Structure ◽  
Free Living ◽  
Free Living Amoeba

The fine structure of a species of small free-living amoeba, Hartmanella astronyxis, has been investigated. The mitochondria resemble those of other species of amoeba. Structureless bodies of about the same size as mitochondria are sometimes found in association with them. Double membranes are common in the cytoplasm, and may show granules along their outer borders. The nuclear membrane is a double-layered structure, with a honeycomb structure evident in tangential sections. The cell membrane is also double-layered, or occasionally multi-layered.

scholarly journals FINE STRUCTURE OF MEMBRANOUS AND MICROFIBRILLAR SYSTEMS IN THE CORTEX OF PARAMECIUM CAUDATUM

1971 ◽  
Vol 49 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Richard D. Allen
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Microscope Study ◽  
Electron Microscope Study ◽  
Three Dimensional ◽  
Paramecium Caudatum ◽  
Fibrillar Material ◽  
Muscular Function ◽  
Branching System

An electron microscope study of the cortex of Paramecium caudatum has revealed new details pertinent to several unresolved problems. The lateral boundaries of the alveoli do not regularly follow the crests of the polygonal ridges and thus their staining with silver cannot account for the external lattice seen by light microscopists. A granulo-fibrillar material is present, however, within the peaks of the ridges, which would account for the external lattice if so stained. Perforations are present between adjacent alveoli which make the whole mosaic of alveolar sacs within the cell's cortex continuous—both the membranes and the lumen. A microfibrillar system exhibiting a cross-striated pattern lies in the superficial cortex. These bands are inserted at their ends in the epiplasm and have a fine structure and arrangement suggesting a muscular function. The infraciliary lattice is a branching system of fibers with electron-opaque posts at the center of each branching locus. This system is distinct from the striated bands in morphology and in space. The epiplasm is discontinuous along the crests of the ridges, which may account for the pellicles' disposition to tear along these lines. A three-dimensional drawing is presented to show the interrelationships between the above membranous and microfibrillar systems.

Ultrastructure of Astroloba and Haworthia Pollen Wall

1972 ◽  
Vol 30 ◽  
pp. 220-221
Author(s):  
S. K. Majumdar
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Microscope Study ◽  
Electron Microscope Study ◽  
Chromosome Morphology ◽  
Pollen Wall

Pollen wall morphology has been employed by a number of investigators to assess the interspecific and intergeneric relationships in various groups of plants. Relatively little information is available, however, on the ultrastructure of the pollen wall in the tribe Aloineae. Recent report has dealt with the electron microscope study of Gasteria pollen wall which showed an identical pollen wall anatomy of the four studied species. Since species and genera of the tribe Aloineae are similar in gross chromosome morphology it was considered of interest to study the fine structure of the pollen wall of Astroloba and Haworthia as a prelude to further investigations on the interrelationship among the genera. Pollen of Astroloba spiralis, A. skineri, Haworthia viscosa and H. limifolia was collected fresh and incorporated in agar pellets.

scholarly journals The Fine Structure of Some Retinal Photoreceptors

1960 ◽  
Vol 7 (1) ◽  
pp. 87-92 ◽  
Author(s):  
M. F. Moody ◽  
J. D. Robertson
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Cell Membrane ◽  
Microscope Study ◽  
Electron Microscope Study ◽  
Double Membrane ◽  
Double Structure ◽  
Rods And Cones ◽  
Retinal Photoreceptors ◽  
Bounding Surfaces

An electron microscope study has been made of octopus and amphibian photoreceptors, after fixing with KMnO4 and embedding in araldite. What has previously been seen as a single dense stratum bounding the tubular compartments (octopus) or the double membrane discs (rods and cones), now shows a double structure. We interpret this as showing that these tubules and discs have similar bounding surfaces, which are probably directly related to the cell membrane. This is confirmed by the finding that the tubules and discs are (at least occasionally) continuous with the cell membrane.

scholarly journals ELECTRON MICROSCOPE STUDY OF SPERMIOGENESIS IN A FIRE-BRAT INSECT, THERMOBIA DOMESTICA PACK

1964 ◽  
Vol 23 (3) ◽  
pp. 431-446 ◽  
Author(s):  
S. R. Bawa
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Microscope Study ◽  
Electron Microscope Study ◽  
Membrane System ◽  
Mature Spermatozoon ◽  
Axial Filament ◽  
Thermobia Domestica ◽  
Complex Membrane ◽  
Coarse Fibers

The fine structure of the mature spermatozoon of the insect Thermobia domestica has been investigated. This flagellate spermatozoon is unique with respect to the relative positions of the centriole, nucleus, mitochondrial nebenkern derivatives, and acrosome along the length of the cell. The acrosome lies at the posterior end of the nucleus. Unlike spermatozoa of most animals, the Thermobia spermatozoon has a nucleus that reveals an unusual lamellar pattern of the material inside of it. This flagellate spermatozoon is also unusual in its tendency to intertwine with other spermatozoa, and during movement the intertwined portion of two (double) spermatozoa is always directed forwards. In the axial filament complex, one of the fibrils of each peripheral double fibril bears a hook-shaped process. An indistinct granular material is seen between the 9 outer coarse fibers. Cytoplasmic tubules, probably corresponding to the "microtubules" of other investigators (67), have been observed around the nucleus, mitochondrial nebenkern derivatives, axial filament complex, and acrosome. A description is given of a complex membrane system which surrounds and separates the main organelles of the cell from each other.

A Scanning Electron Microscope Study of the Frustule Structure of the Freshwater Diatom Melosira Granulata (Ehr.) Ralfs

1973 ◽  
Vol 31 ◽  
pp. 218-219
Author(s):  
W. H. Abbott ◽  
C. O. Pollard
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Microscope Study ◽  
Light Microscope ◽  
Electron Microscope Study ◽  
Scanning Electron Microscope Study ◽  
Scanning Electron ◽  
Conventional Light Microscope ◽  
Freshwater Diatom

Frustules of the freshwater diatom Melosira granulata (Ehr.) Ralfs from a freshwater diatomite of Miocene age and recent frustules of this species from Reelfoot Lake, Tennessee were examined under a scanning electron microscope to determine fine structure generally not seen or poorly seen with the conventional light microscope.The terminology used to describe frustule structure in this study was originated by Hendy.Melosira granulata generally grows in chains of two connected frustules with each frustule containing two valves or halves. The connection between frustules is accomplished by the encasing of the adjacent valves of two frustules by a structure called the girdle (Fig. 1a).

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