1. Chromosome Mutations in Meiosis
April 23, 2019

2. Mutations

3. Mutations
Sometimes pieces of chromosomes are lost, duplicated or moved within a chromosome or to another chromosome during meiosis

4. Mutations
Sometimes pieces of chromosomes are lost, duplicated or moved within a chromosome or to another chromosome during meiosis
These changes are called mutations

5. Mutations
Sometimes pieces of chromosomes are lost, duplicated or moved within a chromosome or to another chromosome during meiosis
These changes are called mutations
These mutations affect many genes in the chromosome and change the proteins made by those genes

6. Some types of chromosome mutations

7. Mutations

8. Mutations
Mutations also occur when cells are exposed to mutagens such as radiation or chemicals

9. Mutations
Mutations also occur when cells are exposed to mutagens such as radiation or chemicals
E.g. some fruit flies exposed to mutagens have legs growing where antennae should be

10. Whole Chromosome Mutations

11. Whole Chromosome Mutations
Whole chromosome mutations can occur in meiosis I (when homologous chromosomes fail to separate) or in meiosis II (when sister chromatids fail to separate)

12. Whole Chromosome Mutations
Whole chromosome mutations can occur in meiosis I (when homologous chromosomes fail to separate) or in meiosis II (when sister chromatids fail to separate)
The result is that one gamete has 2 copies of the same chromosome and the other will have no copy of that chromosome

13. Whole Chromosome Mutations

14. Whole Chromosome Mutations

15. Whole Chromosome Mutations
Usually whole chromosome errors are prevented from being passed along because the offspring either fails to develop or does not live to reach reproductive age and adulthood

16. Whole Chromosome Mutations
Usually whole chromosome errors are prevented from being passed along because the offspring either fails to develop or does not live to reach reproductive age and adulthood
Some chromosome mutations result in genetic disorders or syndromes such as Down syndrome

17. Karyotype

18. Karyotype
A picture of an individual’s chromosomes, arranged by size

19. Karyotype
A picture of an individual’s chromosomes, arranged by size

20. Karyotype

21. Karyotype
Karyotypes can show genetic disorders

22. Karyotype Karyotypes can show genetic disorders
The karyotype of a person with Down syndrome:

23. Karyotype Karyotypes can show genetic disorders
The karyotype of a person with Down syndrome:
A person with Down syndrome has an extra 21st chromosome

24. Karyotype Karyotypes can show genetic disorders
The karyotype of a person with Down syndrome:
A person with Down syndrome has an extra 21st chromosome
This individual is a male because they have a Y chromosome

25. Karyotype Karyotypes can show genetic disorders
The karyotype of a person with Down syndrome:
A person with Down syndrome has an extra 21st chromosome
This individual is a male because they have a Y chromosome
(Females have 2 X chromosomes)

27. Edwards Syndrome

29. Turner Syndrome

30. Textbook Questions
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