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Definition
Understanding evolutionary change through chromosomal studies.
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Example / case study
Humans and chimpanzees share a common ancestor with 24 pairs of chromosomes; two fused to form chromosome #2 in humans. Discovered by: Murray F. Lyon (Lyon Hypothesis, 1961). (T: M.F Leone) Refers to the inactivated X chromosome in female somatic cells (random inactivation).
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Definition
A karyotype is the complete set of chromosomes of an individual, arranged in homologous pairs according to their size, shape and banding pattern.
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Example / case study
Cri-du-chat Syndrome (5p−) – deletion on short arm of chromosome 5. The brain is highly sensitive to gene dosage imbalance.
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Thinkers
Turner’s Syndrome (XO): Female with only one X → no Barr body.
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Definition
A karyotype is the complete set of chromosomes of an individual, arranged in homologous pairs according to their size, shape and banding pattern.
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Example / case study
Cri-du-chat Syndrome (5p−) – deletion on short arm of chromosome 5. Severity depends on proportion and distribution of abnormal cells. Mosaic Down Syndrome – some cells 47,+21; others normal 46. Turner mosaic – some cells 45,X; others 46,XX.
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Thinkers
Turner’s Syndrome (XO): Female with only one X → no Barr body.
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Definition
Refers to the inactivated X chromosome in female somatic cells (random inactivation).
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Example / case study
Calico Cats: Different coat patches due to random X inactivation. Turner’s Syndrome (XO): Female with only one X → no Barr body.
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Definition
Diagnosis: Karyotype (47,XXX); two Barr bodies.
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Example / case study
Cri-du-chat Syndrome (5p−) – deletion on short arm of chromosome 5. Baby after birth cry like cat, microcephaly, wide-set eyes, low-set ears. Intellectual disability, delayed development.
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Definition
Understanding evolutionary change through chromosomal studies.
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Example / case study
Humans and chimpanzees share a common ancestor with 24 pairs of chromosomes; two fused to form chromosome #2 in humans. Discovered by: Murray F. Lyon (Lyon Hypothesis, 1961). (T: M.F Leone) Refers to the inactivated X chromosome in female somatic cells (random inactivation).
Short notes for this Anthropology syllabus heading.