Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Lecture Chpt. 15 Genetics.errors
Document related concepts
Transcript
Nondisjuncti on Homologous pairs do not move apart during Meiosis Nondisjuncti on aneuploidyabnormal number -2n + 1 ex. Down’s trisomic - 2n - 1 ex. Turner’s monosomic monosomic Turner’s Syndrome trisomic Trisomy 21 Trisomic 2n + 1 Down Syndrome / Trisomy 21 Turner Syndrome X monosomic 2n -1 2N + 1 (2N + 2, 2N + 3) Genotype: XXY (XXXY, XXXXY) Phenotype: male, but sexual development Klinefelter’s may be poor. Often Syndrome taller than average, mental development fine (XXY), usually sterile. More X = more mental problems Kleinfelter’s Syndrome Klinefelter’s Syndrome Comment: I have read that George Washington may have had Klinefelter’s. Taller than average, no children 2N +1 Genotype: XXX Phenotype: taller female, but sexual development poor. (Mental impairment common in many reports, not in others???) Trisomy X Edward’s Syndrome Edward’s Syndrome Edward’s Syndrome • • • • Also known as Trisomy 18 Almost every organ system is affected. 1:10,000 live births. Children with full Trisomy 18 generally do not live more than a few months. • Characteristics: small jaw, low-set ears, and a strawberry-shaped head. Patau Syndrome • This person would suffer from serious eye, brain, & circulatory defects as well as cleft palate. • 1:5000 live births. Children rarely live more than a few months. Patau Syndrome Tall Jacob’s Syndrome XYY Lean Acne prone Crooked eye Anger difficulties Some cognitive difficulties Translocations Prader-Willi Deletion on chromosome 15 - father imprinted Angelman Deletion on chromosome 15 - mother imprinted Gene expression and inheritance depends on which parent passed on the gene. Usually caused by different methylations of the DNA. Imprints are "erased" in gamete producing cells and re-coded by the body according to its sex. Prader-Willi Syndrome and Angelman Syndrome Both lack a small gene region from chromosome 15. Male imprint: Prader-Willi Female imprint: Angelman Gene Mutations Chromosome “M” -small circles of DNA located in mitochondria and plastids of plants. Mitochondria reproduces itself and it passes it DNA along to its daughter organelle only. Chromosome “M” - All “M” Chromosomes come from mom These genes help form proteins involved in respiration. Defects in these genes cause Mitochondrial diseases such as mitochodrial myopathy, diabetes, heart disease, Alzheimer’s disease. Cummulative mutations may role play in aging
