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.
American Airlines was founded in 1934 and has developed into a global airlines company that serves 250 cities around the globe with over 3,600 flights a day. American Airlines is the largest airlines in the United States and has one of the largest frequent flyer programs available for their loyal travelers.American Airlines and American Eagle Airlines are under the parent company AMR.American Airlines is committed to providing a high level of service to their passengers as well as their valued employees. Eligible employees of American Airlines receive many benefits that include travel privileges.he main cities where American Airlines has a presence are Boston, Massachusetts; Chicago, Illinois; Dallas/Fort Worth, Texas; Miami, Florida; Philadelphia, Pennsylvania; San Francisco, California; San Jose, California and Tulsa, Oklahoma.