g Write a function cftr(dna) which determines whether a given DNA sequence codes for a normal CFTR. Your implementation should take advantage of either isolate or restriction. For best results use start, end or restriction sequences with at least 15 nucleotides. Furthermore, you can use transcription and then translation to determine whether the resulting amino acid chain is abnormally missing a Phenylalanine. Your function should return a boolean value of True if the given DNA sequence codes for normal CFTR. Otherwise it should return False