Our genetic information is stored in 23 pairs of chromosomes that vary widely in size and shape. Chromosome 1 is the largest and is over three times bigger than chromosome 22.

Source: https://www.ncbi.nlm.nih.gov/books/NBK22266/

There are 23 pairs of chromosomes. But the article is using the phrase "chromosome 1" and "chromosome 22" to refer to "chromosome pairs".

What is the correct term here?

Is there a term referring to a chromosome class or type or something similar?


1 Answer 1


This is standard. For a typical human diploid cell there are two copies of chromosome 1, two copies of chromosome 2, etc; you'd have either two copies of the X chromosome or one X and one Y.

There's not really any ambiguity, the chromosome IDs are always a type or class in some sense.

See for example https://en.wikipedia.org/wiki/Karyotype

  • $\begingroup$ Is it because of the said ambiguity that in mitosis chromosome number remains constant till anaphase and doubled after anaphase upto cytokinesis. Also chromosome number is halved in meiosis 1 but DNA is halved(again) in meiosis 2 $\endgroup$
    – Aurelius
    Sep 3, 2023 at 17:50
  • $\begingroup$ I remember our teacher telling us that after DNA replication both sister chromatids are together called 1 chromosome but after sister chromatids separate each sister is treated as an individual chromosome $\endgroup$
    – Aurelius
    Sep 3, 2023 at 17:55

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