Chromosome

Part of speech: noun

Pronunciation: /ˈkɹəʊ.məˌsəʊm/

Definitions

1. A linear structure composed of DNA and associated proteins that plays a vital role in genetic inheritance and regulates cell division processes
2. An organized assembly of DNA strands and proteins that is crucial for the transmission of genetic information and the orderly separation during cell replication
3. A thread-like structure formed from DNA combined with proteins that is essential for heredity and ensuring proper cell division during the reproductive process

Etymology: Chromosomes were named for their behaviour under a microscope. Biologists who stained cells with dyes noticed that certain threadlike bodies in the nucleus took up colour strongly, and the name combines Greek "khrôma", meaning colour, with "sôma", meaning body. The word was coined in German as "Chromosom" in the 19th century, and English took it from there. The name is therefore a description of a laboratory technique rather than of the structure's job. The threads were visible only because dye made them stand out, and their importance for heredity was worked out much later, so the word says nothing about the genetic role that now defines it. The "chromo-" element in the word also appears in other scientific terms, such as "chromatic," which shares the same Greek root for colour.

Synonyms: DNA strand