1. C-Notes: Chromosomal Abnormalities (Errors of Meiosis)
Stnd: 2c
C-Notes: Chromosomal Abnormalities (Errors of Meiosis)
2/14/2014
Objective:
SWBAT explain the problems with meiotic spindles not separating properly during Meiosis, which causes abnormalities in offspring.

2. How can genetic material be changed?
Incorrect number of chromosomes
Non-Disjunction (Chromosomal Aberration)
Problems with meiotic spindle causes the homologous chromosomes NOT to separate properly during Meiosis I
Or sister chromatids fail to separate during Meiosis II
Leading to TOO MANY or TOO FEW chromosomes in one daughter cell.
either an extra or missing chromosome causing Aneuploidy (wrong # of chromosome. Ex: XXX)
Found in Chromosomes # 8,12,13,14,15,18, & 21)
Breakage of Chromosomes
Deletion
Duplication
Inversion
translocation
Certain drugs have become popular among teens and young adults at dance clubs and raves.

3. Changes in chromosome structure
deletion
loss of a chromosomal segment
duplication
repeat a segment
inversion
reverses a segment
translocation
move segment from one chromosome to another
error of replication
error of crossing over

4. Certain drugs have become popular among teens and young adults at dance clubs and raves.

5. How do changes in the genetic material (alteration of chromosomes) of an organism lead to changes in the traits of that organism?
This leads to gametes with irregular numbers of chromosomes.
Certain drugs have become popular among teens and young adults at dance clubs and raves.

6. How does these alteration of chromosomes effect an organism?
Baby has wrong number of chromosomes
“SOMY” means Mutations
Involve individual extra/missing chromosomes
Usually result in early miscarriage
Certain drugs have become popular among teens and young adults at dance clubs and raves.

7. Because it does NOT result in miscarriage 3 copies of Chromosome 21
Why is the extra # 21 chromosomemore tolerated by organisms ? (Down Syndrome)
Because it does NOT result in miscarriage
3 copies of Chromosome 21
Characteristic of facial appearance and other varying effects
Varying levels of retardation
Frequently correlates with age of mothers.  
Certain drugs have become popular among teens and young adults at dance clubs and raves.

8. Down syndrome & age of mother
Mother’s age
Incidence of Down Syndrome
Under 30
<1 in 1000 30
1 in 900 35
1 in 400 36
1 in 300 37
1 in 230 38
1 in 180 39
1 in 135 40
1 in 105 42
1 in 60 44
1 in 35 46
1 in 20 48
1 in 16 49
1 in 12
Rate of miscarriage due to amniocentesis:
1970s data 0.5%, or 1 in 200 pregnancies
2006 data <0.1%, or 1 in 1600 pregnancies

9. Human development (body cells/ Autosomes) (chromosome #1-22) are more tolerant of wrong numbers than Sex Chromosome (pair #23/ X & Y)
But abnormalities in Sex Chromosomes produces a variety of distinct syndromes in humans
XXY = Klinefelter’s syndrome male
XXX = Trisomy X female
XYY = Jacob’s syndrome male
XO = Turner syndrome female
What are the Sex Chromosomes abnormalities?
Certain drugs have become popular among teens and young adults at dance clubs and raves.

10. Sterile (cant have kids) Associated with heart defects
What is Turner’s Syndrome: Monosomy X?
XO Females
Phenotypically female (short stature, swelling, broad chest, webbed neck, los set ears, etc)
Sterile (cant have kids)
Associated with heart defects
Certain drugs have become popular among teens and young adults at dance clubs and raves.

11. XXY Male What is Klinefelter’s syndrome? one in every 2000 live births
have male sex organs, but are sterile
feminine characteristics
some breast development
lack of facial hair
tall
normal intelligence
Certain drugs have become popular among teens and young adults at dance clubs and raves.

12. Klinefelter’s syndrome
How many Barr bodies would you expect?

13. XYY Males What is Jacob’s syndrome? 1 in 1000 live male births
extra Y chromosome
slightly taller than average
more active
normal intelligence, slight learning disabilities
delayed emotional immaturity
normal sexual development
Certain drugs have become popular among teens and young adults at dance clubs and raves.

14. XXX Females What is Trisomy X? 1 in every 2000 live births
produces healthy females
Why?
Barr bodies
all but one X chromosome is inactivated
Certain drugs have become popular among teens and young adults at dance clubs and raves.