Why girls are all there and boys are missing parts!! 4.3 Complex Inheritance Why girls are all there and boys are missing parts!!

Warm-up Essential Question What are the chromosomes that determine your sex? Essential Question How are traits passed on the X-Chromosome through generations?

Inherited Diseases- Recessive Albinism- absence of melanin pigment Male pattern Baldness Hemophilia – the inability for the blood to clot correctly Red-Green color blindness

Inherited Diseases- dominant Huntington’s Disease- affects nervous system in people 30-50 years old. Achondroplasia- most common form of Dwarfism. Shortened arms, legs body trunk but normal width

Sex-Linked traits A gene found on the X chromosomes Because, males only have one X chromosome, they have a much greater chance of the gene expressed. Females would have to be homozygous recessive in order to have the gene expressed Carrier: someone who has a gene that is not expressed Ex: colorblindness

Let’s try it!

Pedigree a pedigree is a diagram showing genetic relationships between members of a family By charting diseases and other traits through a family, we can see patterns These patterns can tell us about dominant/recessive and whether it is sex linked Note that a girl with a dominant sex link trait CAN’T be a carrier!

Practice! Fill out the genotypes of the family

Blood Typing Co-dominance 3 different alleles: A, B, O Create 4 different blood types: A, AB, B, O Type O is recessive (basically a lack of A or B alleles), all others can “share” Each parent “donates” one blood type allele to offspring Create antigens on each red blood cell – how your body knows it’s your blood

Which alleles are there? Blood type A, could be: _____ or _____ Blood type B, could be ______ or _____ Blood type AB: ______ Blood type O: _______

Blood Typing Rh factor – Rhesus (monkey) factor Rh+ dominant, Rh- recessive Each parent donates one to offspring, either + or -

Universal donor: type O No antigens present Universal recipient: AB+ Already has antigens for both, will not create antibodies and fight off any type

Your Family tree Pick 6 traits Record your phenotype and predicted genotype for each trait Research this trait as far back as you can Create 6 pedigree charts – one for each trait Due Friday November 2