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Genetic Mutations Power Point Shortened (2).pptx
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- 2. What is aGenetic Mutation? A mutation is a change in the nucleotide sequence of DNA Bases can be accidentally deleted, added, inverted (flipped), or replaced with different bases Mutations can occur in the DNA in any of our cells, but only mutations in our sex cells (gametes) will be passed on to our offspring Amoeba Sisters- Mutations What effect will this have on protein synthesis?
- 3. What Causes Mutations? 1.Can occur randomly during the process of DNA replication 2. Radiation: ultraviolet (UV) rays, x-rays 3. Chemicals: asbestos, benzene found in tobacco
- 4. Types of Mutations: 1.Point Mutations 1. One single base is changed 2. Examples: Substitution or Frameshift 2. Chromosomal Mutations 1. Entire segments of a chromosome are altered 2. Examples: Inversion, Translocation, Deletion, Duplication
- 5. Substitution and Frameshift PointMutations
- 6. Substitution Mutation One single DNAbase is swapped for a different one Three Types: Silent, Nonsense, and Missense
- 7. Missense Mutation DNAbase that is substituted codes for a different amino acid
- 8. Nonsense Mutation DNAbase that is substituted, accidentally codes for a STOP codon
- 9. Silent Mutation OneDNA base is changed but it does not change the amino acid produced
- 10. Insertion Mutation Oneor more bases are inserted into the original DNA base sequence Shifts the entire codon reading frame so all amino acids after the mutation are different
- 11. Deletion Mutation Oneor more bases are deleted This is also called a frameshift mutation
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- 14. Inversion Rotation ofpart of the chromosome
- 15. Translocation Part ofa chromosome breaks off and attaches to another chromosome
- 16. Translocation Karyotype What elseis wrong with this karyotype?
- 17. Deletion Removal ofpart of a chromosome
- 18. Duplication A segmentof a chromosome is repeated
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- 20. Genetic Disorders Mutationsin DNA can result in many different diseases and disorders Diseases occur because a gene now codes for an abnormal protein or enzyme It could cause a wrong amino acid to be produced, and as a result the protein may not fold correctly If this protein or enzyme is very important for the functioning of our body, serious complications can result
- 21. Sickle-Cell Anemia RecessiveInherited disorder Red blood cells have an abnormal sickle shape This shape makes it difficult for them to carry oxygen and causes them to clump together Caused by a missense mutation of the gene that codes for hemoglobin
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- 24. Hemophilia Blood disorderin which individuals are unable to make a certain blood protein that aids in the clotting process Disorder is caused by a recessive gene that is carried on the x chromosome Since males only have one x chromosome, hemophilia typically occurs in males Hemophilia and t he Royal Family
- 25. Hemophilia Inheritance Pattern Females are only carriers Males are the only affected individuals because they only have one x chromosome 50% of the male offspring created by a female carrier will have the disease
- 26. Tay-Sachs Disease RecessiveInherited Disorder Babies lack the enzyme that breaks down lipids in the brain Without the enzyme, lipids build up and kill brain cells Disease is fatal and death occurs when a child is several years old
- 27. Cystic Fibrosis Mostcommon genetic disorder Caused by a recessive gene on chromosome 7 Causes glands to produce a thick mucus that clogs lungs and damages the digestive system
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- 29. Down Syndrome Alsocalled “trisomy 21” because individuals have an extra chromosome 21 Occurs when chromosomes do not separate correctly during meiosis Characterized by developmental delay and physical abnormalities
- 31. Klinefelter’s Syndrome • Maleshave an extra X chromosome • Have more feminine characteristics • Produce decreased levels of testosterone • Usually sterile
- 32. Turner’s Syndrome • Femalemissing an X chromosome • Females are usually underdeveloped and sterile