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.
US Airways was earlier known as America West Airlines, provides passenger and freight airline carrier in the United States. The airlines headquarters is in Tempe, Arizona, United States. The company employs about 32,213 people worldwide for its services. US Airways is owned by US Airways Group. The airline company has approximately 3,028 flights daily through 1,210 mainline flights and 1,818 express flights to about 198 locations in United States of America, Canada, Mexico, Europe, the Middle East, the Caribbean, and Central and South America.