Presentation on theme: "A photograph of a persons chromosomes (cut up and arranged in order)"— Presentation transcript:
1 A photograph of a persons chromosomes (cut up and arranged in order) KaryotypesA photograph of a persons chromosomes (cut up and arranged in order)
2 How many chromosomes are present How many chromosomes are present? Is this a somatic (body) cell or a gamete?
3 Chromosomal Genetic Disorders 1. Numerical:When an individual is missing either a chromosome from a pair (monosomy) or has more than two chromosomes of a pair (trisomy, tetrasomy, etc).Examples:Down Syndrome – (Trisomy 21) an individual has three copies of chromosome 21Turner Syndrome – (monosomy) an individual is born with only one sex chromosome, an X.
4 Examples continuedKlinefelter's syndrome – also known as XXY syndrome, a condition in which males have an extra X sex chromosome.Edwards Syndrome – (Trisomy 18) an individual has three copies of chromosome 18
9 2. Structural: When the chromosome's structure is altered. a. Deletions: A part of a chromosome is missing or deleted.b. Duplications: A portion of the chromosome is duplicated, resulting in extra genetic material.
10 Other structural disorders: Translocations: When a portion of one chromosome is transferred to another chromosome.Inversions: A portion of the chromosome has broken off, turned upside down and reattached, therefore the genetic material is inverted.Rings: A portion of a chromosome has broken off and formed a circle or ring. This can happen with or without loss of genetic material.Isochromosome: Formed by the mirror image copy of a chromosome segment including the centromere.