Sex-linked Inheritance

Sex Determination

  Why are some diseases more common in men than women?   Ex. Color blind 8 % of males, 8 % of males, but only 0.5% females but only 0.5% females

Sex-Linked Traits Male and Female

Sex-Linked Traits in Human  Red/Green Colorblindness  Hemophilia

Hemophilia

Hemophilia   Queen Victoria of England was a carrier 

  X B X B Normal Female   X B X b Carrier Female (normal)   X b X b Disorder female ( you need two copies of the gene in females to express)   X B Y Normal male   X b Y Disorder male Why do you think sex linked traits effect men more than women?

 Would this person X H X h have hemophilia? Is this male or female?  Would person X H Y have hemophilia? Is this male or female?

Sex- Linked Cross   If a mother who is a carrier for Hemophilia has a child with a father who has normal blood. What percent of the children will have Hemophilia? What percent of the boys?

Sex-Linked Cross   Cross a female that has normal vision with a male that is colorblind. What percent of their children will be colorblind?

X B X O - only females can show both colors- CALICO

Problems with Chromosome Number 5. Monosomy – only one of a particular type of chromosome (2n -1) 6. Trisomy – having three of a particular type of chromosome (2n + 1) 7. Polyploidy – having more than two sets of chromosomes; triploids (3n = 3 of each type of chromosome), tetraploids (4n = 4 of each type of chromosome).