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Genetics 16-18 . April 17, 2014. 16. ATA CTG ACT TGC CAG TTC. COMPLIMENTARY DNA STRAND TAT GAC TGA ACG GTC AAG COMPLIMENTARY RNA STRAND UAU GAC UGA ACG GUC AAG AMINO ACID SEQUENCE TYR ASP STOP THR VAL LYS. 17. GENE MUTATIONS.
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Genetics 16-18 April 17, 2014
16. ATA CTG ACT TGC CAG TTC • COMPLIMENTARY DNA STRAND TAT GAC TGA ACG GTC AAG • COMPLIMENTARY RNA STRAND UAU GAC UGA ACG GUC AAG • AMINO ACID SEQUENCE TYR ASP STOP THR VAL LYS
17. GENE MUTATIONS Point mutation is a mutation in which one nucleotide is substituted for another. Sickle Cell Anemia is caused by a point mutation. Changes one amino acid. Frameshift mutation involves the insertion or deletion of a nucleotide in the DNA sequence. Cystic fibrosis is a frameshift mutation. Changes many amino acids.
17. Nondisjunction The failure of chromosomes to separate during meiosis Cell with 47 chromosomes or a cell with 45 chromosomes. Example is Down’s Syndrome has 47 chromosomes.
17. Silent mutation Has no affect because it codes for the same amino acid.
17. Causes of mutations Mutagens – agents that cause mutations. Examples – UV radiation, tar and nicotine, formaldehyde Replication errors (DNA polymerase corrects errors)
18. Gene Therapy The replacement of a defective or missing gene, or the addition of a new gene, into a person’s genome to treat a disease. Goal is to cure genetic disorders. It is successful if the replacement gene is transcribed in the person’s cells.