The first practical windmills had sails that rotated in a horizontal plane, around a vertical axis. According to Ahmad Y. al-Hassan, these panemone windmills were invented in eastern Persia as recorded by the Persian geographer Estakhri in the ninth century.
Genetic testing is a type of medical test that identifies changes in chromosomes, genes, or proteins. The results of a genetic test can confirm or rule out a suspected genetic condition or help determine a personâs chance of developing or passing on a genetic disorder.More than 1,000 genetic tests are currently in use, and more are being developed. Several methods can be used for genetic testing:Molecular genetic tests (or gene tests) study single genes or short lengths of DNA to identify variations or mutations that lead to a genetic disorder.he results of a genetic test can confirm or rule out a suspected genetic condition or help determine a personâs chance of developing or passing on a genetic disorder. More than 1,000 genetic tests are currently in use, and more are being developed.
Genetic ancestry testing is the use of DNA information to make inferences about someoneâs deep ancestry, hundreds or thousands of years into the past. Genetic genealogy on the other hand combines DNA testing with genealogical and historical records, and typically makes use of large databases to identify matches.