SCIENCE

1. Meiosis MistakesMeiosis Mistakes
Human chromosomeHuman chromosome
abnormalitiesabnormalities

2. NondisjunctionNondisjunction
 Failure of homologous chromosomes toFailure of homologous chromosomes to
separate during cell divisionseparate during cell division

3. ResultsResults
1 too1 too manymany OR 1 tooOR 1 too few chromosomesfew chromosomes

4.  Trisomy:Trisomy:
 one too manyone too many
47 chromosomes47 chromosomes
 Monosomy:Monosomy:
 one too fewone too few
45 chromosomes45 chromosomes

5. How can we diagnose theseHow can we diagnose these
abnormalities?abnormalities?
 KaryotypesKaryotypes
 Picture of chromosomesPicture of chromosomes in a dividing (div.)in a dividing (div.)
cellcell
 Arranged in orderArranged in order by sizeby size

6. Why might this be useful?Why might this be useful?
 Prenatal testingPrenatal testing
 amniocentesisamniocentesis

7. Down’sDown’s syndromesyndrome
 Short statureShort stature
 Round faceRound face
 Developmental DelaysDevelopmental Delays
 Eyelids thatEyelids that
Cover inner cornerCover inner corner
Of eyesOf eyes
Trisomy-21Trisomy-21

8. Klinefelter’sKlinefelter’s syndromesyndrome
 Affects onlyAffects only malesmales
 SterileSterile
 Varying affectsVarying affects
Extra X ChromosomeExtra X Chromosome

9. Edward’sEdward’s syndromesyndrome
 Growth deficiencyGrowth deficiency
 Feeding difficultiesFeeding difficulties
 Breathing difficultiesBreathing difficulties
 Developmental delaysDevelopmental delays
 Underdevelopped organsUnderdevelopped organs
 Small headSmall head
 Low-set, malformed earsLow-set, malformed ears
 Cleft lip/palateCleft lip/palate
 Overlapped, flexed fingersOverlapped, flexed fingers
 Trisomy 18Trisomy 18

10. PatauPatau syndromesyndrome
 heart defectsheart defects
 sloping forehead,sloping forehead,
 small or missing eyes,small or missing eyes,
 low set ears,low set ears,
 cleft palatecleft palate
 extra fingers and toesextra fingers and toes
 Developmental delaysDevelopmental delays
 Trisomy-13Trisomy-13

11.  Who determines the sex ofWho determines the sex of
the child?the child?

12.  THE FATHER!THE FATHER!