Search results
Results from the WOW.Com Content Network
The organization of chromosomes into distinct regions within the nucleus was first proposed in 1885 by Carl Rabl.Later in 1909, with the help of the microscopy technology at the time, Theodor Boveri coined the termed chromosome territories after observing that chromosomes occupy individually distinct nuclear regions. [6]
The largest regions on each chromosome are the short arm p and the long arm q, separated by a narrow region near the center called the centromere. [1] Other specific regions have also been defined, some of which are similarly found on every chromosome, while others are only present in certain chromosomes. Named regions include: Arms (p and q ...
Metaphase cells with low CENP-E levels by RNAi, showing chromosomes unaligned at the metaphase plate (arrows). These chromosomes are labeled with antibodies against the mitotic checkpoint proteins Mad1/Mad2. Hec1 and CENP-B label the centromeric region (the kinetochore), and DAPI is a specific stain for DNA.
The physical role of the centromere is to act as the site of assembly of the kinetochores – a highly complex multiprotein structure that is responsible for the actual events of chromosome segregation – i.e. binding microtubules and signaling to the cell cycle machinery when all chromosomes have adopted correct attachments to the spindle, so ...
Prokaryotic cells have entirely different structures for organizing their DNA (the prokaryotic chromosome equivalent is called a genophore and is localized within the nucleoid region). The overall structure of the chromatin network further depends on the stage of the cell cycle.
The average cell will divide between 50 and 70 times before cell death. As the cell divides the telomeres on the end of the chromosome get smaller. The Hayflick limit is the theoretical limit to the number of times a cell may divide until the telomere becomes so short that division is inhibited and the cell enters senescence.
Chromosome decondensation (also known as relaxation or decompaction) into expanded chromatin is necessary for the cell's resumption of interphase processes, and occurs in parallel to nuclear envelope assembly during telophase in many eukaryotes. [2] MEN-mediated Cdk dephosphorylation is necessary for chromosome decondensation. [2] [5]
This is an accepted version of this page This is the latest accepted revision, reviewed on 23 January 2025. 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 ...