The answer is 20. Duplicated chromosome has two sister chromatids, identical copies of the chromosome. These two chromatids are joined at the region called centromere. Therefore, one duplicated chromosome has one centromere and two sister chromatids. If there are 20 duplicated chromosomes in a cell, there will be 20 centromeres.
The biggest airlines flying to United States: American Airlines flights to United States, Delta flights to United States, Southwest Airlines flights to United States. Regions in the USA - United States. Airlines flying to the USA - United States - by city.
DIA serves over 170 destinations including 20 international cities in seven countries. DIA is the largest hub of Frontier Airlines and the fourth-largest hub for United Airlines. Southwest Airlines continues to grow rapidly at the airport and the airport is the airline's fourth largest base.t 34,000 acres (140 km 2) , DIA is by far the largest land area commercial airport in the United States. Dallas/Fort Worth International Airport is a distant second at 78 square kilometres (30 sq mi). The 327-foot (100 m) control tower is one of the tallest in North America.