The dimensions of the White House are as follows. The length is 168 feet (51.2 meters). The width is 152 feet with the porticoes. Without the porticoes it is 85 feet 6 inches (26.1 meters). The height is 60 ft 4 inches on the north. On the south it is 70 feet. The fence of the White House covers 18 acres.
23. In the electrophoretic mobility shift assay (EMSA), DNA-protein interactions are detected by changes in the mobility of a DNA fragment bound to a protein. A DNA fragment containing a putative protein binding site is first radiolabeled and then incubated in the presence of sequence-specific DNA binding proteins.
Point Mutations. A point mutation is a single-letter swap -- an exchange of two bases (adenine to cytosine, for example) at a single location in the DNA molecule. Since the sequence of letters in a gene determines the sequence of amino acids in the protein it encodes, a point mutation can change the amino acid sequence of the resulting protein. Sometimes a change in the protein's amino acid sequence can have dramatic results. For example, sickle cell disease occurs when a single-point mutation in the gene that encodes the hemoglobin molecule results in deformed red blood cells.