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

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somewhere safe!

• Student Profile

• Class Enrollment Password: Biology

• TurnItIn Class ID– 2nd period: 1435724– 4th period: 1435726– 6th period: 1435727