Search results
Results from the WOW.Com Content Network
The nucleoid (meaning nucleus-like) is an irregularly shaped region within the prokaryotic cell that contains all or most of the genetic material. [1] [2] [3] The chromosome of a typical prokaryote is circular, and its length is very large compared to the cell dimensions, so it needs to be compacted in order to fit.
The bacterial DNA is not packaged using histones to form chromatin as in eukaryotes but instead exists as a highly compact supercoiled structure, the precise nature of which remains unclear. [6] Most bacterial chromosomes are circular, although some examples of linear chromosomes exist (e.g. Borrelia burgdorferi). Usually, a single bacterial ...
This is an accepted version of this page This is the latest accepted revision, reviewed on 8 December 2024. DNA molecule containing genetic material of a cell This article is about the DNA molecule. For the genetic algorithm, see Chromosome (genetic algorithm). Chromosome (10 7 - 10 10 bp) DNA Gene (10 3 - 10 6 bp) Function A chromosome and its packaged long strand of DNA unraveled. The DNA's ...
These structures are invaginations of the plasma membrane observed in gram-positive bacteria that have been chemically fixed to prepare them for electron microscopy. [2] They were first observed in 1953 by George B. Chapman and James Hillier, [3] who referred to them as "peripheral bodies." They were termed "mesosomes" by Fitz-James in 1960. [4]
Linear bacterial plasmids have been identified in several species of spirochete bacteria, including members of the genus Borrelia notably Borrelia burgdorferi, which causes Lyme disease. [3] Though not forming a nucleus, the DNA is condensed in a nucleoid. Plasmids encode additional genes, such as antibiotic resistance genes.
Hans Ris (June 15, 1914 – November 19, 2004) was an American cytologist and pioneer electron microscopist.His studies of chromosome structure revealed the importance of non-histone proteins, and along with evolutionary biologist Lynn Margulis, he was one of the first to recognize that blue-green algae were a special type of bacteria.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Bacterial conjugation is the transfer of genetic material (plasmid) between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells. [1] Discovered in 1946 by Joshua Lederberg and Edward Tatum, [ 2 ] conjugation is a mechanism of horizontal gene transfer as are transformation and transduction although ...