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.
Located in Dallas, Texas, Southwest Airlines is the worldâs largest low-cost carrier, and carries the greatest number of domestic passengers of any U.S. airline. It flies to 86 destinations in 42 states and Puerto Rico. It operates more than 3,400 flights daily, and only flies Boeing 737s.