Cytology

-
.
Cytology, branch of biology concerned with the study of the structure and function of cells as individual units, supplementing histology, which deals with cells as components of tissues. Cytology is concerned with the structure and activities of the various parts of the cell and cell membrane; the mechanism of cell division; the development of sex cells, fertilization, and the formation of the embryo; cell derangements such as those occurring in cancer; cellular immunity; and the problems of heredity.

Cytology, branch of biology concerned with the study of the structure and function of cells as individual units, supplementing histology, which deals with cells as components of tissues. Cytology is concerned with the structure and activities of the various parts of the cell and cell membrane; the mechanism of cell division; the development of sex cells, fertilization, and the formation of the embryo; cell derangements such as those occurring in cancer; cellular immunity; and the problems of heredity.

Comments

Post a Comment

Popular posts from this blog

Hanaoka Seishu

-
Image
A stamp depicting the image of Hanaoka Seishu. Hanaoka Seishu (1760-1835), Japanese physician and pioneer of anesthetic surgery. Hanaoka studied traditional Sino-Japanese medicine, as well as what was then known about Western surgery in Japan. For over two decades he experimented with various drugs. Ultimately he created mafutsusan, an anesthetic compound made from six traditional plant-based drugs, including the alkaloids aconite (from the monkshood plant) and datura (from jimsonweed ). In 1805, using mafutsusan as an anesthetic, Hanaoka removed a tumor during breast cancer surgery. This was the world's first recorded successful surgical operation with anesthesia. Later, Hanaoka used the drug for other surgical operations, developing techniques for bladder stone removal and for amputation. Hanaoka attracted many students, and his surgical techniques became known as the Hanaoka method.
Read more

Modern Agriculture

-
In the N and W United States the era of mechanized agriculture began with the invention of such farm machines as the reaper, the cultivator, the thresher, and the combine. Other revolutionary innovations, e.g., the tractor, continued to appear over the years, leading to a new type of large-scale agriculture. Modern science has also revolutionized food processing; refrigeration, for example, has made possible the large meatpacking plants and shipment and packaging of perishable foods. Urbanization has fostered the specialties of market gardening and truck farming. Harvesting operations (see harvester) have been mechanized for almost every plant product grown. Breeding programs have developed highly specialized animal, plant, and poultry varieties, thus increasing production efficiency. The development of genetic engineering has given rise to genetically modified transgenic crops and, to a lesser degree, livestock that possess a gene from an unrelated species that confers a desired quali...
Read more

Brahe, Tycho

-
Image
Brahe, Tycho (1546-1601), Danish astronomer, who made precise, comprehensive astronomical measurements of the solar system and more than 700 stars . The data Brahe accumulated was superior to all other astronomical measurements made until the invention of the telescope in the early 17th century. Brahe was born in Knudstrup in southern Sweden (then part of Denmark). He studied law and philosophy at the universities of Copenhagen and Leipzig; at night, however, Brahe busied himself with observing the stars. With no instruments other than a globe and a pair of compasses, he succeeded in detecting grave errors in the standard astronomical tables, and set about correcting them. In 1572 he discovered a supernova in the constellation Cassiopeia . After Brahe had spent some time traveling and lecturing, Frederick II, king of Denmark and Norway, offered to provide Brahe with funds to construct and equip an astronomical observatory on the island of Hven (now Ven). Brahe accepted the proposal,...
Read more