1. Achondroplasia

2. Karyotypes and Nondisjunction

3. Karyotype Picture of a persons’ chromosomes
Reveals extra or missing chromosomes
Allows doctors to detect some genetic disorders

4. Karyotypes Picture taken during metaphase of mitosis
Chromosomes are condensed and consist of 2 sister chromatids
DNA is stained prior to taking the picture. Similar DNA sequences glow similarly
Arranged by decreasing size

5. Telomeres They serve a protective function The ends of a chromosome
Their degradation leads to aging and cancer

6. Nondisjunction

7. Nondisjunction Occurs when Sister Chromatids fail to separate
Can happen in Meiosis I or Meiosis II
Wrong number of chromosomes in a gamete

8. Nondisjunction
Down syndrome occurs because of an extra chromosome 21

9. Down syndrome
Occurs because of nondisjunction
Also called trisomy 21

10. Nondisjunction

11. Monosomy
Only 1 of a particular chromosome

12. Nondisjunciton and Sex Chromosomes