Pedigrees and Sex Linked Traits Outcome I will explore how traits are inherited through generations by solving autosomal and sex-linked pedigrees.

Sex Chromosomes X and Y are sex chromosomes The other 22 pairs are autosomal(body) chromosomes Males = XY Females = XX Not true homologous pairs X has more genes

X and Y Males Females Get Y from dad Get X from mom Get one X from dad Get one X from mom

Sex-linked traits X-linked The inheritance pattern of genes located on the X chromosome

Hemophilia Video https://www.phd.msu.edu/divisions/pediatric-adolescent-hematology-oncology/educational-videos-about-hemophilia.html

X-Linked Punnett Square Sex linked H=normal & h=hemophilia Cross: XHXh x XhY What is the chance that their son will have hemophilia? What is the chance that their daughter will have hemophilia? XH Xh XH Xh Xh Xh Y XH Y Xh Y 50% 50%

Sex-linked worksheet Working with your table, complete the sex linked worksheet in your notes. You will have 6 minutes!

Pedigrees a chart that shows how a trait (phenotype) is inherited through a family

Pedigrees circles: females squares: males shaded: individual with trait/disease Half-shaded: carriers for a trait but does not express the trait.

Generation / Individual Practice Generations are the rows in a pedigree Individuals are labeled across a pedigree Lines down represent offspring I II III 1 2 1 2 3 1 2 3 4

What do we call this individual? Carrier Quick Quiz Individual A is A male who expresses the trait A female who does not express the trait A male who does not express the trait A female who does express the trait What do we call this individual? Carrier

Quick Quiz Individual D is A male who expresses the trait A female who does not express the trait A male who does not express the trait A female who does express the trait

Quick Quiz Individual H is A male who expresses the trait A female who does not express the trait A male who does not express the trait A female who does express the trait

Outcome I will explore how traits are inherited through generations by solving autosomal and sex-linked pedigrees.

Fugates of Kentucky: Skin Bluer than Lake Louise http://www.youtube.com/watch?v=4iJVWMR4Uq0

Fugates of Kentucky: Skin Bluer than Lake Louise Methemoglobinemia blood disorder with an abnormal amount of methemoglobin - a form of hemoglobin reduced ability to release oxygen to tissues - gives blood a bluish color

Autosomal Recessive Trait appears only when two parents by chance carry the hidden allele Affected individual inherits both recessive alleles Example: sickle cell disease Who could be a carrier? Color in the carriers

Autosomal Dominant Trait appears in every generation, in about half of descendants (assuming a heterozygous carrier) Affected individual has at least one dominant allele Example: Huntington’s disease

X-linked Recessive Mother passes on to half of sons; half of daughters carry it.  Father never passes on trait. Examples: Hemophilia, color blindness Why do more men have it? Who could be a carrier? Can men be carrier?

X-linked Dominant Father passes trait to all daughters; no sons.  Mother passes on to half of children. Example: Rett syndrome

Outcome I will explore how traits are inherited through generations by solving autosomal and sex-linked pedigrees.