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MUTATIONS!

MUTATIONS!. Part One. MUTATIONS: WHAT ARE THEY ?. MUTATIONS:. are changes in the genetic material of the cell. can occur at the level of an individual DNA strand ( a point mutation ) or to an entire chromosome ( a chromosomal mutation ). MUTATIONS:.

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MUTATIONS!

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  1. MUTATIONS! Part One

  2. MUTATIONS:WHAT ARE THEY ?

  3. MUTATIONS: • are changes in the genetic material of the cell. • can occur at the level of an individual DNA strand (a point mutation) or to an entire chromosome (a chromosomal mutation)

  4. MUTATIONS: • usually lead to a decrease, rather than an increase, of information. • A loss of information in the cell leads to a loss of some function.

  5. Information is lost….

  6. Information is lost….

  7. Informationis lost….

  8. Information is lost….

  9. The loss of information means that most mutations areeither harmfulor have no effect.

  10. The loss of information means that most mutations areeither harmfulor have no effect.

  11. The loss of information means that most mutations areeither harmfulor have no effect.

  12. The loss of information means that most mutations areeither harmfulor have no effect.

  13. . Now and then a mutation will offer a benefit to an organism.

  14. . However, the idea that a single mutation would lead to a huge, dramatic change in a single generation (like the X-Men characters) is just wrong.

  15. TYPES OF MUTATIONS: • Point mutations are caused by random errors in the copying process (during transcription)

  16. TYPES OF MUTATIONS: • Chromosomal mutations occur when chromosomes fail to properly separate during meiosis

  17. ChromosomalMutations: chromosome nucleosome DNA double helix coils supercoils histones

  18. ChromosomalMutations: • changes in the number • or structure of chromosomes

  19. ChromosomalMutations: • changes in the number • or structure of chromosomes • typically harmful in humans

  20. ChromosomalMutations: • can occur in four different ways: • deletion, duplication, inversion and translocation

  21. ChromosomalMutations: DELETION

  22. ChromosomalMutations: DELETION DUPLICATION

  23. ChromosomalMutations: DELETION DUPLICATION INVERSION

  24. ChromosomalMutations: DELETION DUPLICATION INVERSION TRANSLOCATION

  25. Non-Disjunction: • is the failure of the chromosomes • to properly separate during • meiosis Meiosis II: Meiosis I: non-disjunction homologous chromosomes fail to separate

  26. Non-Disjunction: • leads to organisms with the • wrong number of chromosomes • causes birth defects like Down’s • Syndrome (trisomy-21)

  27. POINTMutations: chromosome nucleosome DNA double helix coils supercoils histones

  28. POINTMutations: • are changes in single base pairs of DNA • can lead to production of faulty • (misshapen) proteins, or no • protein at all

  29. POINTMutations: • often have no • effect:UCC • codes for • serine, for • example, but so • does UCU, UCA • or UCG • that change the last letter in a DNA • triplet may lead to the same amino acid

  30. POINTMutations: • that do this are called sense or • silent mutations

  31. POINTMutations: • which lead to • a different • amino acid, • however, are • called missense • mutations • Depending on the amino acid, • these can be good, bad or neutral

  32. POINTMutations: • which lead to • a stopcodon • (UAA, UAG or • UGA) are called • nonsense • mutations • These lead to loss of function • and are usually bad

  33. POINTMutations: • Sense, missense and nonsense • mutations are typically caused • by substitution of one nucleotide • for another, changing the • meaning of only one codon. • Deletion or insertion of an entire • nucleotide leads to frameshift !

  34. Frameshift Mutationsalter everything that follows: THE DOG ATE THE RAT MAN THE HOG ATE THE RAT MAN THE DOG ATE HER ATM AN… THE OGA TEH ERA TMA N…

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