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.

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  • 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

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  • Chromosome 3 (human) — Short and long arms Chromosome 3 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 3 spans almost 200 million base pairs (the building material of DNA) and represents about 6.5 percent …   Wikipedia

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