q arm of a chromosome
The long arm of a chromosome. All human chromosomes have 2 arms — a short arm and a long arm — that are separated from each other only by the centromere, the point at which the chromosome is attached to the spindle during cell division. By international convention, the short arm is termed the "p arm" while the long arm of the chromosome is termed the "q arm." Examples of usage of p and q: Loss of part of 5p (the short arm of chromosome 5) results in the cat cry syndrome. Trisomy (an extra copy) of part of 21q (the long arm of chromosome 21) causes Down syndrome. Origin of p and q as chromosome arms: The symbol "p" was chosen to designate the short arm because "p" stands for "petit", "small" in French. The letter "q" was selected to signify the long arm merely because "q" is the next letter in the alphabet.

Medical dictionary. 2011.

Look at other dictionaries:

  • Long arm of a chromosome — The long arm of a chromosome is termed the q arm. All human chromosomes have 2 arms, the p (short) arm and the q (long) arm. They are separated from each other only by a primary constriction, the centromere, the point at which the chromosome is… …   Medical dictionary

  • p arm of a chromosome — The short arm of a chromosome. The p comes from the French petit meaning small. All human chromosomes have 2 arms the p (short) arm and the q (long) arm that are separated from each other only by a primary constriction, the centromere, the point… …   Medical dictionary

  • Short arm of a chromosome — The short arm of a human chromosome is symbolized by convention as p . The p comes from the French petit meaning small. All human chromosomes have 2 arms, the p (short) arm and the q (long) arm. They are separated from each other only by a… …   Medical dictionary

  • Chromosome 5 (human) — Chromosome 5 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 5 spans about 181 million base pairs (the building blocks of DNA) and represents almost 6% of the total DNA in cells.… …   Wikipedia

  • Chromosome 15q trisomy — is an extremely rare genetic disorder, caused by a chromosomal aberration in which there is an excess copy of the long ( q ) arm of human chromosome 15. The disorder is also known as Distal Duplication 15q and Partial Duplication 15q Syndrome.… …   Wikipedia

  • q — 1. quintal. 2. the long arm of a chromosome (opposed to p). {Phrase Origin: the short arm was named p, from French petit, and q was chosen as the name for the long arm as q is the letter after p in the alphabet} …   Australian English dictionary

  • q — 1. In cytogenetics, symbol for long arm of a chromosome (in contrast to p for the short arm). 2. Abbreviation for [L.] quodque, each; every. 3. q. Symbol for heat. * * * coulomb [electric quantity]; electric charge; flow; 1,4 glucan branching… …   Medical dictionary

  • Chromosome 7 (human) — Chromosome 7 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 7 spans more than 158 million base pairs (the building material of DNA) and represents between 5 and 5.5 percent of the… …   Wikipedia

  • Chromosome 15q partial deletion — is an extremely rare human genetic disorder, caused by a chromosomal aberration in which the long ( q ) arm of one copy of chromosome 15 is deleted, or partially deleted. If the mother s copy of the chromosomal arm is deleted, Angelman syndrome… …   Wikipedia

  • Chromosome — For a non technical introduction to the topic, see Introduction to genetics. Diagram of a replicated and condensed metaphase eukaryotic chromosome. (1) Chromatid – one of the two identical parts of the chromosome after S phase. (2)… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”