Genetics & Related Disorders Terms and Symptoms

2 Terms You Must Know… Diploid – number of chromosomes in most body cells. Humans have 46. Haploid – having ½ the number of chromosomes. Sperm & egg cells.

So now answer this… Which statement describes the beginning and end products of meiosis? –A. One diploid cell becomes two haploid cells. –B. One haploid cell becomes two diploid cells. –C. One diploid cell becomes four haploid cells. –D. One haploid cell becomes four diploid cells.

The Answer Is…

Genetic Disorders Abnormal condition that a person inherits through genes or chromosomes. –Causes include: 1. Mutation (change) in DNA 2. Changes in structure of chromosomes 3. Changes in number of chromosomes

Down Syndrome Extra copy of chromosome 21 Chromosomes fail to separate during meiosis Older mothers (40+) Intellectual disability, heart defects, eye problems, poor muscle tone 55 years average life

Sickle Cell Disease Clogs blood vessels & cannot carry as much oxygen AA = normal Aa = produce normal/abnormal blood cells aa = sickle cell disease

Sickle Cell Statistics Occurs in 1 out of every 500 African American births More common in regions where malaria is found – sickle cells protect against the disease Antibiotics, transfusions, bone marrow transplant = treatments Can live well into middle age or beyond

Klinefelter’s Syndrome XXY – affects only males Chromosomes fail to separate in meiosis Little to no body/facial hair; sterile; learning disabilities ; overweight

Turner Syndrome X – females missing the 2 nd X chromosome Chromosomes fail to separate in meiosis Short, stocky, swollen hands/feet, short neck, sterile

Example of Meiosis resulting in Turner’s syndrome

Hemophilia The blood clots slowly or not at all Recessive allele on X chromosome Most common in males because males have only one X chromosome

Hemophilia genetically linked

Queen Victoria’s Hemophilic Family

Trisomy 18 Clenched fists Mental delay Small head/jaw Low set ears ½ die before age1; others may live to teen years

Genetic disorders don’t define who you are. Would you know there was ever a problem? Tay-sachs HemophiliaDown SyndromeKlinefelter’s Syndrome Turner’s Syndrome Epilepsy