MA+Chromosome+HW+3

Human Genetics 2 Homework 20.2c and 20.4
 * Define:
 * carriers: when a heterozygous person has an allele for a characteristic
 * autosomal recessive disorder: when a child is affected by a disease but the parents are not
 * autosomal dominant disorder: when a child has a disease because the parents do
 * autosomes: non sex chromosomes
 * sex chromosomes: chromosomes that determine the sex of an individual...XX=female XY=male
 * sex linked: when an allele is found on a sex chromosome
 * X linked: an allele that is found on the X chromosome
 * X linked dominant: when the allele is passed onto daughters
 * X linked recessive: allele is found mostly in males...females can get it but less likely.
 * Describe diseases (You will need to know how they are inherited ie X-linked recessive or autosomal dominant. You will also need to know the gene that is mutated and what damage that causes to the body)
 * Cystic Fibrosis
 * autosomal recessive disorder
 * when chloride ions fail to pass through the plasma membrane...this causes lack of water which causes mucus build up in the lungs
 * it causes painful breathing and eventually death
 * PKU
 * autosomal recessive metabolic disorder
 * lack enzyme needed for metabolism of amino acid phenylalanine
 * amino acid is found in blood and urine...if detected a diet is put in place until babies brain is fully developed
 * Sickle Cell Disease:
 * autosomal recessive
 * red blood cells are not biconcave disks like normal blood
 * caused by adnormal hemoglobin
 * causes poor circulation, anemia, and low resistance to infection
 * Marfan Syndrome
 * autosomal dominant disorder
 * caused by defect in an elastic connective tissue, fibrillin
 * causes dislocated legs, long limbs and fingers, and caved in chest


 * Huntington Disease
 * neurological disorder that leads to progressive degeneration of brain cells
 * autosomal dominant disorder
 * caused by mutated copy of the gene for a protein called huntington
 * Color blindness
 * X linked recessive disorder
 * see brighter green as tans
 * olive green as brown
 * reds as reddish browns
 * some can't tell red from green at all
 * Muscular Dystrophy
 * X linked recessive disorder
 * breaks down the muscles...causes falls and difficulty in movements
 * death occurs by 20
 * caused by abscence of protein dystrophin
 * Hemophilia
 * x linked recessive disorder
 * hemophilia a=abscence or minimal presence of clotting factor known as factor VIII
 * hemophilia b=abscence of clotting factor IX
 * persons blood does not clot or does so very slowly
 * Tay-sachs:
 * autosomal recessive disorder
 * results from a lack of the enzyme hexosaminidase
 * in babies....nerves become damaged and eventually baby goes blind then paralyzed and dies