Spanish wine person a year. The country has an abundance of native grape varieties, with over 400 varieties planted throughout Spain though 80 percent of the country's wine production is from only 20 grapes—including the reds Tempranillo, Garnacha, and Monastrell; the whites Albariño from Galicia, Palomino, Airen, and Macabeo; and the three cava grapes Parellada, Xarel·lo, and Macabeo. Major Spanish wine regions include the Rioja and Ribera del Duero, which are known for their Tempranillo production; Valdepeñas, drunk by Unamuno and Hemingway, known for high quality tempranillo at low prices; Jerez de la Frontera, the home of the fortified wine Sherry; Rías
Petite mutation Petite mutation petite (ρ–) is a mutant first discovered in the yeast "Saccharomyces cerevisiae". Due to the defect in the respiratory chain, 'petite' yeast are unable to grow on media containing only non-fermentable carbon sources (such as glycerol or ethanol) and form small colonies when grown in the presence of fermentable carbon sources (such as glucose). The petite phenotype can be caused by the absence of, or mutations in, mitochondrial DNA (termed "cytoplasmic Petites"), or by mutations in nuclear-encoded genes involved in oxidative phosphorylation. A neutral petite produces all wild type progeny when crossed with wild type. petite mutations can