240 likes | 444 Views
Pedigrees and Sex Linked Traits. Outcome I will explore how traits are inherited through generations by solving autosomal and sex-linked pedigrees. X and Y are sex chromosomes The other 22 pairs are autosomal(body) chromosomes Males = XY Females = XX Not true homologous pairs
E N D
Pedigrees and Sex Linked Traits Outcome • I will explore how traits are inherited through generations by solving autosomal and sex-linked pedigrees.
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 Sex Chromosomes
X and Y • Males • Get Y from dad • Get X from mom • Females • 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? 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
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?
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.