Most women produce one egg per month. Use your knowledge of the menstrual cycle and oogenesis to explain how Dan’s mother produced an egg carrying the u allele.

On a spring day, a middle-latitude city (about 40? north latitude) has a surface (sea-level) temperature of 10 ? c. if vertical soundings reveal a nearly constant environmental lapse rate of 6.5 ? c per kilometer and a temperature at the tropopause of –55 ? c, what is the height of the tropopause?