* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download MUTATIONS • Mutations are errors made in the DNA sequence that
Epigenetics of neurodegenerative diseases wikipedia , lookup
Human genome wikipedia , lookup
Skewed X-inactivation wikipedia , lookup
Nucleic acid double helix wikipedia , lookup
Primary transcript wikipedia , lookup
Genome evolution wikipedia , lookup
Genealogical DNA test wikipedia , lookup
Cancer epigenetics wikipedia , lookup
Cre-Lox recombination wikipedia , lookup
DNA damage theory of aging wikipedia , lookup
Extrachromosomal DNA wikipedia , lookup
DNA supercoil wikipedia , lookup
Saethre–Chotzen syndrome wikipedia , lookup
Genomic library wikipedia , lookup
Expanded genetic code wikipedia , lookup
X-inactivation wikipedia , lookup
Designer baby wikipedia , lookup
Neocentromere wikipedia , lookup
Population genetics wikipedia , lookup
Genetic engineering wikipedia , lookup
Koinophilia wikipedia , lookup
Nucleic acid analogue wikipedia , lookup
Site-specific recombinase technology wikipedia , lookup
Deoxyribozyme wikipedia , lookup
Cell-free fetal DNA wikipedia , lookup
Vectors in gene therapy wikipedia , lookup
Therapeutic gene modulation wikipedia , lookup
Non-coding DNA wikipedia , lookup
History of genetic engineering wikipedia , lookup
Genome editing wikipedia , lookup
Genome (book) wikipedia , lookup
Microsatellite wikipedia , lookup
Helitron (biology) wikipedia , lookup
No-SCAR (Scarless Cas9 Assisted Recombineering) Genome Editing wikipedia , lookup
Oncogenomics wikipedia , lookup
Artificial gene synthesis wikipedia , lookup
Genetic code wikipedia , lookup
Microevolution wikipedia , lookup
MUTATIONS Mutations are errors made in the DNA sequence that are inherited These errors may have deleterious side effects, no effect, or positive side effects for an organism Errors made may change the protein and if the protein is essential for the cell structure or metabolism then the outcome can be a damaged or even a dead cell Types of Mutations 1. silent mutation has no effect on the cell; it occurs usually in the noncoding regions (introns) of the DNA, that could be cut out and never show up can also be caused by the redundancy in the genetic code (different triplets code for the same amino acid) 2. missense mutation involves a substitution that results in a different aa being placed in the sequence ex/ sickle cell anemia 3. nonsense mutation involves a change in the DNA sequence that causes a stop codon to replace a codon for an aa; only the part of the protein prior to the stop codon will be produced. they are often lethal to the cell. Frameshift Mutations Frameshift mutations are caused by insertions (an extra nucleotide is inserted) or deletions (one or more nucleotides are removed from the DNA sequence (see Fig.1, p.260) If a frameshift mutation happens to insert one or two nucleotides, it can have devastating effects because every amino acid in the polypeptide chain If a frameshift mutation inserts three nucleotides, it will just insert an extra amino acid into the chain Point Mutations Point mutations are caused by a substitution (the wrong base pair is substituted for the correct one) Point mutations can be silent, missense or nonsense See Fig.1, p.260 Chromosomal Changes Translocation is when a part of one chromosome is exchanged with another nonhomologous chromosome. Ex/ Chromosome 14 may get a segment from chromosome 8, who gets a segment from chromosome 14 (a form of cancer results). Inversion is when a gene segment is separated then inserted in reverse; no loss in genetic material but the gene may be disrupted or come under transcriptional control. changes in chromosome structure have helped humans evolve. out of the 23 pairs of chromosomes we have 18 that are almost identical to those of chimpanzees and gorillas and the other 5 are different only because of inversions or translocations. Transposable Genes discovered by Barbara McClintock fragments of DNA that move from one location to another may cause a disruption in transcription if they fall within a coding region Causes of Genetic Mutations spontaneous mutations are caused by errors in the genetic machinery Ex/ DNA Polymerase I misses a point mutation induced mutations are a result from exposure to mutagenic agents (agents that can alter the structure of DNA.) Ex/ ultraviolet radiation, X rays, and chemicals Seatwork Pg. 263 # 1 - 9