Calvin Bridges (1889-1938) is known for his contributions to the field of genetics. 1889 was a common year starting on Tuesday (see link for calendar). ... 1938 was a common year starting on Saturday (link will take you to calendar). ... Genetics (from the Greek genno γεννώ= give birth) is the science of genes, heredity, and the variation of organisms. ...

His work with sex linked traits in the fruit fly Drosophila melanogaster suggested that chromosomes contained genes. Later Nettie Maria Stephens was able to prove this hypothesis by examining the chromosomes of the fruit flies. Bridges wrote a couple of papers presenting the proof. He thanked her as "Miss Stevens" without stating what her contribution was nor referring to her PhD. Binomial name Drosophila melanogaster Meigen, 1830 Drosophila melanogaster (Black-bellied Dew-lover) a dipteran (two-winged) insect, is the species of fruit fly that is commonly used in genetic experiments; it is among the most important model organisms. ... Figure 1: Chromosome. ... This stylistic schematic diagram shows a gene in relation to the double helix structure of DNA and to a chromosome (right). ... Nettie Maria Stephens (1861-1912) was a biologist and geneticist. ...

Bridges' best-known contribution among Drosophila researchers is his observation and documentation of the polytene chromosomes found in larval salivary gland cells. The banding patterns of these chromosomes are still used as genetic landmarks by contemporary researchers. To increase cell volume, some specialised cells undergo repeated rounds of DNA replication without cell division (endomitosis), forming a giant polytene chromosome. ...

He died on December 27, 1938. Reports differ as to whether this was due to syphilis, or to heart failure as a complication of a heart valve infection. December 27 is the 361st day of the year in the Gregorian Calendar. ... 1938 was a common year starting on Saturday (link will take you to calendar). ... Depression-era U.S. poster advocating early syphilis treatment Syphilis (historically called lues) is a sexually transmitted disease (STD) that is caused by a spirochaete bacterium, Treponema pallidum. ...