Transcript Williams, 5E model lesson ppt

http://www.youtube.com/watch?v=PCVO9c9q4tE
Autosomal Dominant Disorder:
 Inheritance of only one copy of the mutated gene
is necessary to be affected by the Autosomal
Dominant Disorder, Huntington’s Disease and
others.
 Reproduction is then more dangerous because
children have a 50% chance of inheriting the
mutated gene if their parent has it.
 This is because the mutated gene is expressed in
both dominant Homozygotes and Heterozygotes.
Autosomal Recessive Disorder:
 Whereas, Autosomal Recessive Disorders require
two mutated genes be inherited to be affected
(most genetic disorders are recessive).
 Ex: Cystic Fibrosis, Sickle-Cell Anemia, and TaySachs Disease.
 All would be Homozygous Recessive for these
disorders.
 Recessive disorders are usually inherited when both
parents are “carrying” the mutated recessive gene (they are
Heterozygotes).
Most people do not know they
are a CARRIER until they have a
child with the disease.
The value of studying Genetics
is in understanding how we can
predict the likelihood of
inheriting particular traits.
How to set up a Punnett Square:
Dihybrid Crosses:
 The cross or mating between two organisms where two
genes are studied are called a DIHYBRID cross.
 The genes are located on separate chromosomes, so
the traits themselves are unrelated.
GgWw X GgWw