1. DNA and Mutations

2. 5 Mutation Facts Write down five facts about mutations as we go through the following videoclips Video 1 Video 2 – Repair Video 3 – Repair Addition and Deletion Mutations

3. Mutation = change in the DNA code Lead to frameshifts – the message is no longer correctly passed = protein altered (changed, no change, or incomplete)

4. 3 Types of DNA Mutations: 1. Substitution - one base for another Ex: Sickle-cell Anemia GAG (Valine) into GUG (Glutamic acid) 1.

5. 2. Insertion - extra bases Ex: Fragile X syndrome – CGG repeat 5-100 repeats = no harm longer repeats grow longer from one generation to the next (as many as 4000 repeats). 2.

6. 3. Deletion - a section of DNA is lost Ex: Duchenne Muscular Dystrophy (DMD) DMD gene codes for dystrophin (protein) protein holds skeletal muscle cells together DMD = no protein to bind muscle cells together 3.

7. Chromosome Mutations Chromosome: Coiled DNA and proteins Karyotype

8. Chromosome 21 “Trisomy 21’ Down Syndrome

9. Kleinfelter’s Syndrome - XXY Male Develop some breast tissue Little body hair typically tall Infertility results - no sperm

10. Turner’s Syndrome – X No Y means Turner’s people are female. no ovaries develop  don’t undergo puberty and they are sterile. Hormone treatment cures all but the sterility. Other symptoms: short stature, webbed skin and low hairline at the neck

11. Reflection 1.DNA codes for proteins. If DNA is mutated, how might this cause a disease? (Connect proteins to disease). 2.How is it possible for two identical twins, with identical DNA sequences, have different traits – for instance one gets cancer and one does not.

12. What is Epigenetics?Epigenetics the study of changes in phenotype (appearance) or gene expression caused by mechanisms other than changes in the DNA