1. Mutations and Chromosomal Disorders

4. Mutation or birth defect?

5. Mutations
Random Accidents/Generally Insignificant or Beneficial or Bad
Accidents- Replications/Transcriptions
Mitosis
Meiosis
Gene Mutation: More Common

6. Do all mutations affect the organisms?
No!
Mutations may occur in a gene that is turned off in a cell (ex. Kidney cell vs. Heart Cell)
When this occurs, there is no affect on the organism!
Example: Concert Sound Board

7. Mutagen Factors in the environment that cause mutations
Can you think of a few?
X-Rays, UV waves, various chemicals

8. Mutations Gene Mutation Chromosome Mutation Substitution Deletion
Point mutation
Deletion
Addition
Chromosome Mutation
Nondisjunction
Fragmentation
translocation
Inversion
Addition
Deletion
Polyploidy

10. Translocation

11. A mutation can only be passed on to offspring IF
THE MUTATION IS PRESENT IN THE GAMETES / SEX CELLS

12. Gene Mutations Substitution (point mutation)-changes one codon
Deletion (frameshift mutation)-everything changes after the removal of that nucleotide

13. Chromosomal Mutation
Affects the whole chromosome and all genes on chromosomes
Will be more detrimental!
Mutations passed on if occur in sex cells

14. Nondisjunction
Chromosomes that normally separate during Meiosis stay together and can cause several genetic disorders in humans
Examples: Down Syndrome, Turner’s, Klinefelter’s

15. Down’s Syndrome
-extra copy of
chromosome # 21
Turner’s Syndrome
-underdeveloped sexual
characteristics
-webbed neck

16. Klinefelter’s Syndrome
-two X chromosomes
and a Y
-male with underdeveloped sex organs

17. Polyploidy Polygenetic Trait-
Cells have some multiple of the normal chromosome number
Example: Plants with Polyploidy are usually larger with larger fruit

18. Common Genetic Disorders

19. Sex-linked Disorders
Hemophilia
Color-Blindness
Male Pattern Baldness

20. Autosomal Disorders Sickle Cell- sickle shaped blood cells
Tay –Sachs- death by the age of 4
Cannot breakdown lipids in the brain
PKU-Caused by mutation and cannot break down phenylalanine
Cystic Fibrosis-(refer to video on Active Transport) Missing gene to control formation of mucus
Huntington’s Disease-fatal but do not appear until 30 years old-due to breakdown of the brain cells

21. Detecting Genetic Disorders
Karyotyping
Amniocentesis
Chorionic villus sampling
Ultrasound

22. Karyotype: Normal

23. Karyotype: Edward’s Syndrome

24. Edward’s Syndrome

25. Amniocentesis (Ultrasound)

26. Amniocentesis

27. Amniocentesis

28. Ultrasound

30. Genetic Engineering

31. Definition
The process of producing altered DNA, usually by breaking a DNA molecule and inserting new genes

32. Genetic Screening
When a person’s genetic make-up is analyzed to determine the possibility of genetic disorders for themselves and that could be passed on to future offspring
Think of a couple who were choosing their embryo for invitro fertilization

33. Recombinant DNA (Gene Splicing)
DNA from two different species is joined together
Provides a way of producing large amounts of sometimes rare substances
Example: Insulin and clotting factors that treat Hemophilia
What is used to cut DNA? (Hint: Electrophoresis)
Restriction Enzymes

34. Gene Therapy
The process of correcting genetic defects by transferring normal genes to cells that have defective genes
Sometimes normal genes are introduced to the cell by means of virus or bacteria
Used in both Plants and Animals