1. Warm Up Complete Edpuzzle on pedigrees
If you haven’t completed Edpuzzle from yesterday do so now
You will have 10 minutes before we start the notes

2. What are they?? How do we use them?
Karyotypes
What are they??
How do we use them?

3. Normal Karyotype--male

4. Normal Karyotype--female

5. Is this person female or male?

6. How are DNA samples obtained for karyotypes?

7. What to look for? Are there 46 chromosomes?
Are there 2 identical pairs of each autosome and 2 sex chromosomes?
Are there any rearrangements between chromosomes or large deletions?

8. Trisomy 21 or Down Syndrome
1 in 700 births
47 chromosomes XY or XX
#21 Trisomy Nondisjunction 3

9. Correlation between mother’s age and Trisomy 21 incidence

10. Turners syndrome caused by Nondisjunction
Monosomy

11. Is this a normal karyotype??
Male or Female?
Is this a normal karyotype??
XXY Male (Extra X)

12. Klinefelter syndrome XXY on 23rd pair
Male with some female characteristics
small testes that do not produce as much testosterone as usual
Delayed puberty
Reduced body hair
infertility

13. Deletion—18 Q Deletion Syndrome

14. If there are chromosomal number abnormalities, how do they form?
Meiosis: the process of creating sperm or egg from a diploid cell
If there is a mistake when chromosomes are separating, then the resulting sperm or egg will have too many or too few chromosomes.

15. Nondisjunction

16. What we can’t see Individual DNA strands or genes
The number of genes in any given area of a chromosome.
The presence or location of small mutations. (Scientists cannot predict diseases caused by small mutations within genes.

17. Other chromosomal disorders that can arise?

18. Problems with chromosomes
Duplication: copied parts of chromosome A B C D A B C D

19. Problems with chromosomes
Deletion: missing parts of chromosome A B C D A D

20. Problems with chromosomes
Inversion: parts of chromosome tched A B C D A C B D

21. Chromosomal mutations
Deletion
Duplication
Inversion
Translocation

22. Human genetic disorders from deleterious genes
Sometimes the alleles inherited contribute to disorders and not from the number or shape of the chromosomes.
Sex-linked: genes found on X or Y chromosome
Recessive: requires 2 allele copies to express disorder
Dominant: requires only 1 allele copy to express disorder

23. Recessive disorders

24. Dominant disorder