3. Free electives: Free electives are courses in addition to the Core Curriculum and major requirements sufficient to reach a minimum of 120 credit hours for graduation. Students may graduate with more but not less than 120 credit hours.
The four major North American deserts of this type are the Chihuahuan, Sonoran, Mojave and Great Basin. Others outside the U.S. include the Southern Asian realm, Neotropical (South and Central America), Ethiopian (Africa) and Australian. The seasons are generally warm throughout the year and very hot in the summer.
Most deserts lie between 15Â° and 35Â° north and south of the equator. They were created by air that rises over the equator and comes down over the Tropic of Cancer and the Tropic of Capricorn. All over the world many deserts lie in these regions. 1  Land over the equator becomes very hot. 2  The hot and wet air rises and it rains a lot in these areas.