Figure Detail. As mentioned, sickle-cell anemia is the result of a change in a single nucleotide, and it represents just one class of mutations called point mutations. Changes in the DNA sequence can also occur at the level of the chromosome, in which large segments of chromosomes are altered.he result is the deletion of a DNA sequence in one chromosome, and the insertion of a DNA sequence in the other chromosome. Â© 2014 Nature Education Adapted from Pierce, Benjamin. Genetics: A Conceptual Approach, 2nd ed.
Also established in 1984, the Texas Division of Southwestern Bell Telephone, with headquarters at Dallas, became one of the largest nongovernmental employers in the state, serving 6.2 million customers in 549 Texas communities.
After experimenting with alternative food items, he opened three Taco-Tia stands between 1954 and 1955, which he later sold to his partners. He then opened the first Taco Bell in Downey, California on March 21, 1962. The first Taco Bell franchise was sold in 1964 and the company went public in 1969. In 1978, Bell sold the chain to PepsiCo. The chain was spun off along with Pepsi's other fast food restaurant holdings as Tricon Global Restaurants in October 1997.