1 / 14

Chapter 6: Chromosome Mutations

Chapter 6: Chromosome Mutations. *Chromosome mutations/aberrations. Variation in chromosome number: *aneuploidy *euploidy *polyploidy. Nondisjunction. Homologous chromosomes: during anaphase I. Sister chromatids: during anaphase II. Monosomy.

fionan
Download Presentation

Chapter 6: Chromosome Mutations

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 6: Chromosome Mutations *Chromosome mutations/aberrations Variation in chromosome number: *aneuploidy *euploidy *polyploidy

  2. Nondisjunction Homologous chromosomes: during anaphase I Sister chromatids: during anaphase II

  3. Monosomy *Condition in which one member of a chromosome pair is missing (2n-1) In Drosophila: Haplo-IV are monosomic for chromosome 4 *develop more slowly, reduced size, impaired viability In Plants: Maize, tobacco, evening primrose, Jimson weed *Segmental deletions *Cri-du-chat (46,5p-)

  4. Trisomy *Condition in which one chromosome is present in three copies (2n+1) In Plants: Jimson weed, rice In Drosophila and humans: Has severe effects, usually lethal Exceptions: Patau syndrome, 47,13+ Edwards syndrome, 47,18+

  5. Down syndrome, 47,21+

  6. Polyploidy 1) Addition of one or more sets of chromosomes (replication) 2) Combination of chromosome sets from different species

  7. Arise in several ways: *failure of all chromosomes to segregate during meiosis *two sperm may fertilize an ovum *experimentation Polyploidy Autopolyploidy The benefits of autopolyploid breeding: increased size of plant organs- roots, leaves, flowers fruits, seeds

  8. Polyploidy Allopolyploidy

  9. Variations in Chromosome Structure Deletions

  10. Crossover: A A A A A A A B B B B B B B C C C C C C C D D D D D D D A B C D A B C D A B C D A B C D A B C D Variations in Chromosome Structure Duplications Due to unequal crossing over:

  11. Evolution of hemoglobin genes

  12. Variations in Chromosome Structure Inversions *Paracentric *Pericentric

  13. Variations in Chromosome Structure Translocation

  14. Variations in Chromosome Structure Translocation – unbalanced gametes are produced

More Related