BIO 10/27 NOTES

Recessive: Tay sachs disease. Cystic fibrosis, sickle cell anemia.

Dominant: some human disorders are due to dominant alleles. achondroplasia: form of dwarfism. Huntington’s disease:

Chromosomal abnormalities: nondisjunction: pairs of homologous chromosomes do not separate normally during meiosis. Aneuploidy. She’s going too damn fast in theses power points I’m done. Down syndrome. Turners syndrome . Klinefelters syndrome.

Sex-linked: if x and y are regular chromosomes they can make mistakes too. They reside on the X chromosome. Color blindness, duchenne muscular dystrophy, hemophilia. Found more in men. Ex) woman who’s a carrier for hemophilia, marries a hemophilic. Probability of child having it? Son with it? Daughter with it? 50%, 50%, 50% …………muscular dystrophy:weakening of muscles and loss of coordination hemophilia: missing 1 or more prots required to clot blood.

Multifactorial diseases: lots of symptoms. Heart disease, diabetes, cancer, alcoholism, some mental illnesses.

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NOT DISORDERS

Complete dominance:

Incomplete dominance: some expressing red, some white, appears to be pink. Some alleles are neither dominated not recessive.

Multiple alleles: most genes exist in pops in more than 2 allelic forms. Ex) eye color, blood types.

In Punnet square, because you have multiple alleles, you use I (enzyme for blood) and A (I^A I^A or I^A); B (I^B I^B or I^B); AB (I^A I^B); and O (ii)

Pleiotropy: most genes have multiple phenotypic effects, a property called

Epistasis: there are other things controlling the expression of your genes.

Polygenic inheritance: multiple genes controlling one particular protein. Ex) height and skin color.

Environment can also effect a genes expression.

Pedigree: boys circles, girls squares. Full shade: have it. Half shade: carrying it.

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Rule of addition: dd and DD can get a heterozygote or Dd and Dd can get a heterozygote. Just do the Punnet square dog..

Rule of multiplication used for dihybrid cross.

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