Science Starter: Wednesday, May 22

1. Science Starter: Wednesday, May 22 • How many chromosomes are in a normal human karyotype? • What process makes the gametes (sperm and egg)? • Label the picture to the right.

2. Science Starter, Thursday May 23 • What is the difference between a monosomy and a trisomy? • How is the karyotype of someone with Turner syndrome abnormal? • By looking at a karyotype, can you tell whether the egg or sperm caused the problem? • Why can’t chromosomal disorders be cured?

3. Chromosomal Disorders

4. Vocabulary • Trisomy- a condition in which there are 3 copies of a certain chromosome within the cells of an individual • Monosomy- a condition in which there is only 1 copies of a certain chromosome within the cells of an individual

5. What disorder is this? • Is this individual male or female? • Is this a monosomy or trisomy?

6. Down Syndrome Phenotype Treatment Speech, physical, and occupational therapy Specialized school instruction Plastic surgery • Stunted growth • Mental retardation • Heart defects/disease • Eyelid crease • Decreased lifespan (40’s-50’s)

7. What disorder is this? • Is this individual male or female? • Is this a monosomy or trisomy?

8. Turner Syndrome Phenotype Treatment Growth hormone treatment Special instruction for learning disabilities • Short height • Broad chest • Sterile • Possible learning disabilities

9. What disorder is this? • Is this individual male or female? • Is this a monosomy or trisomy?

10. Klinefelter Syndrome Phenotype Treatment Surgery In vitro fertilization (to have children) Special instruction at school • Less body/facial hair • Breast development • Taller than average • Reduced fertility • Reading/language impairment

11. What Causes Monosomy and Trisomies? • An error in meiosis called “nondisjuction” • This is when chromosomes do not separate properly at the centromere. • Certain gametes get too much DNA, some not enough • Certain factors such as the age of the mother and father can increase the chance of nondisjunction