DNA Gene Mutations What is a gene mutation
- Slides: 21
DNA (Gene) Mutations
What is a gene mutation? ©Parts of DNA will have a base (or more) missing, added, or incorrect ©A mistake in the genetic code ©Wrong instructions wrong building materials wrong structure.
How common are mutations? ©Mutations occurs at a frequency of about 1 in every 1 billion base pairs ©Everybody has about 6 mutations in each cell in their body!
If I have that many mutations, why don’t I look weird? ©Mutations are not always seen. Every part of your DNA doesn’t make a protein or trait. ©Remember introns and exons? ©Some genes are recessive and are therefore hidden, they can be passed to your kids but you don’t notice them.
The most common types of gene mutations are: ©Substitution ©Point mutations ©Frame shift mutations (2 kinds) ©Insertion ©Deletion
DNA (Gene) Mutation Normal DNA: CGA – TGC – ATC Mutated DNA: CGA – TGC - TTC What happened?
DNA (Gene) Mutation #1 Normal DNA: CGA – TGC – ATC Mutated DNA: CGA – TGC - TTC *Adenine was accidentally replaced with thymine *What is this mutation called?
Substitution (point mutation) Normal DNA: CGA – TGC – ATC Amino acids: Ala -- Thr -- stop Mutated DNA: CGA – TGC – TTC Amino acids: Ala -- Thr -- Lys What will happen to the amino acids? How many will be affected?
DNA (Gene) Mutation #2 Normal DNA: CGA – TGC – ATC Mutated DNA: CGA – TAG – CAT - C What happened?
DNA (Gene) Mutations Normal DNA: CGA – TGC – ATC Mutated DNA: CGA – TAG – CAT - C *Adenine was inserted, causing the remaining DNA to shift to the right *What is this mutation called?
Insertion Normal DNA: Amino acids: Mutated DNA: Amino acids: CGA – TGC – ATC Ala -- Thr -- stop CGA – TAG – CAT – C Ala -- Tyr -- Val -- …. . What will happen to the amino acids? How many will be affected?
DNA (Gene) Mutation #3 Normal DNA: CGA – TGC – ATC Mutated DNA: CGA – TCA- TC What happened?
DNA (Gene) Mutation Normal DNA: CGA – TGC – ATC Mutated DNA: CGA – TCA- TC *Guanine was removed, causing the remaining DNA to shift to the left *What is this mutation called?
Deletion Normal DNA: CGA – TGC – ATC Amino acids: Ala -- Thr -- Stop Mutated DNA: CGA – TCA- TC Amino acids: Ala -- Ser --……. What will happen to the amino acids? How many will be affected?
• What causes mutations? © Replication errors © Transcription errors © Cell division errors © Spontaneous changes © Mutagens • Mutagen? What’s that? • “Stuff” that causes mutations when a cell is exposed. • Examples: UV light, Xrays, chemicals, etc.
©What happens to someone with a mutation? ©That all depends…. . ©What kind of mutation it is. ©How many proteins are affected. ©Where in the polypeptide chain is the mutation. ©How many cells does it affect. ©Mutations can be fatal, harmful, beneficial or nuetral.
• Which mutation would have the least effect on an organism? • On intron sections of DNA • On unexpressed recessive traits. • Point mutations/substitutions • Only affects 1 amino acid.
• Which mutation would have the most effect on an organism? • Frame-shift mutations: • Deletions and insertions affect all amino acids after the mutation.
• When would a mutation have the most effect on an organism? • During Meiosis • If gametes are produced with mutations, those mutations will be passed onto the offspring……. • Every cell of organism will contain mutation.
Repairing DNA ©Enzymes proofread the DNA and replace incorrect nucleotides with correct nucleotides. ©The greater the exposure to a mutagen such as UV light, the greater the chance that a mistake will not be corrected.
- Mutation is any mistake or change in the
- Gene mutations
- Gene mutations
- Section 4 gene regulation and mutation
- Section 4 gene regulation and mutations
- Are all mutations bad? *
- Mutations in dna
- Dna types of mutations
- Brca gene mutation
- Hox gene mutation in drosophila
- Hox gene mutation in drosophila
- Dna mutation
- Dna mutation
- Dna mutation
- Dna mutation
- Type of dna mutation
- Gene by gene test results
- Chapter 17 from gene to protein
- Dna, genes and chromosomes relationship
- Define chromosome
- Coding dna and non coding dna
- What are the enzymes involved in dna replication