Mutations powerpoint

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by kritika choudhary
ppt on mutation
description on types of mutation

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Mutations powerpoint

  1. 1.  Changes in the nucleotide sequence of DNA May occur in somatic cells (aren’t passed to offspring) May occur in gametes (eggs & sperm) and be passed to offspring
  2. 2.  Mutations happen regularly Almost all mutations are neutral Chemicals & UV radiation cause mutations Many mutations are repaired by enzymes
  3. 3.  Some type of skin cancers and leukemia result from somatic mutations Some mutations may improve an organism’s survival (beneficial)
  4. 4.  SPONTANEOUS MUTATION INDUCED MUTATION
  5. 5. SPONTANEOUS MUTATION they are mainly caused during dna replication or by incorporation of incorrect nucleotide in the growing dna chain . They occur naturally by changes in DNA sequence during replication.
  6. 6.  Induced mutation are caused by the changes in DNA brought about by some environmental factor called mutagens. E.g.- UV light,x-rays,gamma rays etc…,
  7. 7.  May Involve: › Changing the structure of a chromosome › The loss or gain of part of a chromosome
  8. 8.  Five types exist: › Deletion › Inversion › Translocation › Nondisjunction › Duplication
  9. 9.  Due to breakage A piece of a chromosome is lost
  10. 10.  Chromosome segment breaks off Segment flips around backwards Segment reattaches
  11. 11.  Occurs when a gene sequence is repeated
  12. 12.  Involvestwo chromosomes that aren’t homologous Partof one chromosome is transferred to another chromosomes
  13. 13.  Failure of chromosomes to separate during meiosis Causes gamete to have too many or too few chromosomes Disorders: Klinefelter’s Syndrome – XXY chromosomes › Down Syndrome – three 21st chromosomes › Turner Syndrome – single X chromosome
  14. 14.  Change in the nucleotide sequence of a gene May only involve a single nucleotide May be due to copying errors, chemicals, viruses, etc.
  15. 15.  Include: › Point Mutations › Substitutions › Insertions › Deletions › Frameshift
  16. 16.  Change of a single nucleotide Includesthe deletion, insertion, or substitution of ONE nucleotide in a gene
  17. 17.  Sickle Cell disease is the result of one nucleotide substitution Occurs in the hemoglobin gene
  18. 18.  Inserting or deleting one or more nucleotides Changes the “reading frame” like changing a sentence Proteins built incorrectly
  19. 19.  Original: The fat cat ate the wee rat. Frame Shift (“a” added): › The fat caa tet hew eer at.
  20. 20.  This type of mutations generate a visible morphological alterations. E.g-shape,colour,&size.
  21. 21.  They are fatal in nature leading to the death of individuals .
  22. 22.  Conditional mutations are normal under one condition (permissive), but abnormal under another (restrictive). These are extremely useful for studying processes such as development and DNA replication.
  23. 23.  These mutations cause loss or of some biochemical or nutritional function in the cell.
  24. 24. 2n = 46 34
  25. 25. 2n = 46 35
  26. 26. 2n = 47 36
  27. 27. 2n = 47 37
  28. 28. 2n = 47 38
  29. 29. 2n = 45 39

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