Chromosomes & Karyotypes copyright cmassengale

Chromosomes copyright cmassengale

Chromosome Number All cells in the human body (SOMATIC CELLS) have 46 or 23 pairs of chromosomes Called the DIPLOID or 2n number GAMETES (eggs & sperm) have only 23 chromosomes Called the MONOPLOID or 1n number copyright cmassengale

Nondisjunction Chromosomes may fail to separate during meiosis Resulting gametes may have too few or too many chromosomes Disorders: Down Syndrome – three 21st chromosomes Turner Syndrome – single X chromosome (#23) Klinefelter’s Syndrome – XXY chromosomes (#23) Chi-du-chat – Affects chromosome #5 copyright cmassengale

Normal Male copyright cmassengale 2n = 46

Normal Female 2n = 46 copyright cmassengale

Male, Trisomy 21 (Down’s) 2n = 47 copyright cmassengale

Female Down’s Syndrome copyright cmassengale

Klinefelter’s Syndrome copyright cmassengale

Turner’s Syndrome 2n = 45 copyright cmassengale

Cri-du-chat Syndrome Cri-du-chat is caused by a deletion (the length of which may vary) on the short arm of chromosome 5. Multiple genes are missing as a result of this deletion, and each may contribute to the symptoms of the disorder.

Cri-du-chat syndrome

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