Science Source Feb 2010

Ascaris is a genus of parasitic nematode worms. One species, A. suum, typically infects pigs, while another, A. lumbricoides, affects human population...

Scanning electron micrograph (SEM) of single red blood cell after ion etching in hydrogen for 15 minutes at 2mtorr. Note the pore-like structures, esp...

Transmission electron micrograph of an epithelial cell, parallel to its free surface. This image shows cross sections of cilia and microvilli.

TEM of a myelinated nerve (above) and a number of unmyelinated axons (below).

Transmission electron micrograph showing the rough endoplasmic reticulum and the smooth endoplasmic reticulum. The rough reticulum is seen at right an...

Transmission electron micrograph of smooth muscle in the wall of a small artery. The muscle is seen in cross section at the center of the image, just...

A scanning electron micrograph of household dust.

TEM of a human nerve fiber seen in transverse section. x 8,000

TEM of a human nerve fiber seen in transverse section. x14,000

TEM of sperm from infertile man. Male infertility primarily results from a failure to produce normal spermatozoa. Although the causes are varied, abno...

DNA of two lamda wild type bacteriophages. The ghosts of the phages are also seen in the center of the field. Mag., 100,000x

Cross section of skeletal muscle. Mag., 150.000x

Transmission electron micrograph of a capillary endothelial cell junction in the rete mirabile of the gas bladder of a toadfish. There are minor sites...

Transmission electron micrograph of desmosomes in glial cells in the nerve cord of the annelid worm (Aphrodite aculeata). Desmosomes in invertebrates...

Transmission electron micrograph of the thick surface membranes and the adjacent rough endoplasmic reticulum of two pancreatic acinar cells from a bat...

Transmission electron micrograph of secretory granules associated with an extensive Golgi complex in a cell from Brunner's gland of mouse. In actively...

The smooth endoplasmic reticulum of a steroid secreting endocrine cell.

Transmission electron micrograph of fenestrated cisternae of smooth reticulum in a guinea pig Leydig cell. This steroid secreting endocrine gland cell...

Schematic representation of a generalized mammalian spermatozoon as it would appear with the cell membrane removed. At various levels, cross sections...

Transmission electron micrograph of a longitudinal section of the head from a mammalian sperm. The acrosome, formed from the Golgi apparatus, contains...

Transmission electron micrograph of a longitudinal section of the head and midpiece from a monkey spermatozoon. The rings lining the midpiece form the...

Transmission electron micrograph of a longitudinal section of the junction of the midpiece and prinicipal piece in a mammalian sperm tail. The midpiec...

Two illustrations showing the principal piece and midpiece of a mammalian sperm tail. The upper illustration shows the middle piece, enclosed by a mit...

Transmission electron micrographs of transverse sections from three segments of the mammalian sperm tail. The mitochondrial sheath is clearly visible...

Transmission electron micrograph of rough endoplasmic reticulum in the basal cytoplasm of a pancreatic acinar cell from a bat. The reticular cisternae...

Transmission electron micrograph of lateral cilia of a gill from a mussel. On cells of invertebrates and protozoa, cilia are often closely spaced in p...

Transmission electron micrograph of liver cell cytoplasm showing both rough and smooth endoplasmic reticulum and microbodies.

Transmission electron micrograph of the cytoplasm in a liver cell. The mitochondria, reticulum, and glycogen granules are clearly visible.

Electron micrograph of an antral follicle of mammalian ovary show the oocyte, zona pellucida, and granulosa cells.

Transmission electron micrograph of freeze-fractured plasma membranes of two adjacent cells. The "E Face," (Ectoplasmic) is on the right half of the i...

Transmission electron micrograph of a human Leydig cell. As in other steroid-secreting cells, its most striking ultrastructure feature is the very ext...

This illustration of a rat mammary gland acinus shows th relationships of the myoepithelial cells, the structure of the secretory cells, and the prese...

Transmission electron micrographs illustrating successive stages in condensation of the chromatin and shaping of the nucleus of the spermatid late in...

Transmission electron micrograph of the liver of a normal hamster showing the endoplasmic reticulum. The groups of associated cisternae of the reticul...

A TEM, (24,000x magnification), of an acinar cell from the pancreas of a bat.

Transmission electron micrograph of an interstitial cell from the testis of an opossum. The membranes surrounding the tubules of the reticulum in thes...

Phase-contrast photomicrograph of a mating bacteria. Two mating complexes can be seen. The Hfr cells are elongated; the F cells spherical. With large...

This cross section of the human brain shows the cerebrum, cerebellum, and the basal ganglia. The cortex is depicted by the dotted areas. The horizonta...

Scanning electron micrograph of the surface of the epithelium of a human oviduct, at mid-cycle. The tufts of cilia associated with individual ciliated...

Transmission electron micrograph of a human oocyte in an antral follicle.

Transmission electron micrograph of freeze-fractured nuclear pores. The pores are densely-clustered.

Transmission electron micrograph of a nucleus with a moderate amount of heterochromatin and a nucleolus showing a distinct nucleolonema.

Transmission electron micrograph of a portion of the cytoplasm of a liver cell. Liver cells contain branching and anastomosing tubules that are devoid...

Transmission electron micrograph of a section of reticulum in an adrenocortical cell of a human fetus of 27 weeks. This slightly oblique section passe...

Transmission electron micrograph of a mitochondrion from mouse epididymis. This mitochondrion, from moderately active epididymal epithelium shows an a...

Transmission electron micrograph of a cross section of guinea pig sperm tail at the level of the midpiece, prepared with tannic acid. The organization...

SEM of rods and cones in the eye.

Electron micrographic autoradiograph of mating bacteria. The Hfr (high frequency recombination) cell, (also known as Hfr strain) is the large cell at...

Micrograph of red blood cells.

Myelin sheath in a nerve.