Mistakesin
Meiosis
Nondisjunction• The failure of homologous chromosomes to
separate properly during meiosis.
What should happen Nondisjunction
The results• If the abnormal gametes is fertilized the
results
Polyploidy• the condition where cells have multiple sets of
chromosomes
• usually 3-4 sets
• Most often found in plants, rare in animals
Examples of Polyploidy
Diploid & tetraploid
many plants
Octoploidy
strawberries
Triploid
seedless watermelon
Trisomy• The zygote has an extra chromosome
• Organisms with an extra chromosome sometimes survive
Examples of trisomy in humans
• Trisomy 21: Downs Syndrome
• Trisomy 18: Edwards syndrome
• Trisomy 13: Patau syndrome
• XXY: Klinefelter's syndrome
Monosomy• The zygote is lacking a chromosome
• Organisms lacking one or more chromosomes rarely survive
Examples of monosomy in humans
Monosomy X: Turners Syndrome
Human Karyotype
Karyotype Lab• You will assess a human karyotype and
write a letter to explain the chromosomal abnormality to the patient and patient’s family.
• You will submit your letter via TurnItIn.com
TurnItIn.com Info• Create a user profile, keep this information
somewhere safe!
• Student Profile
• Class Enrollment Password: Biology
• TurnItIn Class ID– 2nd period: 1435724– 4th period: 1435726– 6th period: 1435727