Exploring Mendelian Genetics

GENES are more complicated than Mendel thought ____________________________ the ________________________. = ________________________ Genes ________ the ______ for development, but how plan unfolds also _______ on ______________conditions. “Nature vs Nurture” ENVIRONMENT influences expression of genes provide plan depends environmental

GENES are more complicated than Mendel thought Some traits have ____________ allele __________ = ____________________ EX: blood type Allele choices ___ ___ ___ MULTIPLE ALLELE TRAIT A BO MORE than 2 choices

GENES are more complicated than MENDEL thought Some traits are determined by ____________________________ = __________________ EX: human height. intelligence, skin & eye color POLYGENIC TRAIT MORE THAN ONE GENE

GENES are more complicated than MENDEL thought Traits determined by ____________ _________ have _____ “___________” phenotypes There aren’t just SMART people and DUMB people…. there is a ________________ of intelligences in-between MORE than ONE gene many in-between whole range

GENES are more complicated than MENDEL thought KINDS OF DOMINANCE ____________________ COMPLETE DOMINANCE INCOMPLETE DOMINANCE CO-DOMINANCE

COMPLETE DOMINANCE __________ allele _______ the ___________ one PATTERN ? ____________ allele ________ in a _____ratio in the ____ generation Dominant masks recessive Recessive returns 3:1 F2F2

INCOMPLETE DOMINANCE __________ expected _____ ratio in F 2 generation _____________ organisms with one dominant and one recessive allele show a _________ in-between trait BLENDED DON’T SEE 3:1 Heterozygous Image modified from:

INCOMPLETE DOMINANCE Tay Sachs Disease- Missing an enzyme important for brain development. TT=normal Tt=half the amount of enzyme produced, but sufficient for normal development. tt=no functional enzyme; expression of Tay Sachs disease.

CO-DOMINANCE _______ traits are expressed at ___________ (_____________________) in heterozygote A ________HORSE has ______________ hair and __________ hair side by side BOTH SAME TIME ROAN BOTH RED WHITE NO BLENDING

CO-DOMINANCE Both traits are expressed together (NO BLENDING) in heterozygote Persons with an A allele AND a B allele have blood type AB

Membrane proteins with _______ attached that help cells recognize self = ______________ GLYCOPROTEINS REMEMBER sugars

BLOOD TYPES have more than 2 allele choices = _________________________ The pattern of sugars that is attached is determined by genes Allele choices are: _____________ ABO MULTIPLE ALLELE TRAIT

BLOOD TYPES An A allele tells the cell to put “A” glycoproteins on its surface

BLOOD TYPES A B allele tells the cell to put a different “B” glycoprotein on its surface

BLOOD TYPES An O allele tells the cell NOT to put anything on the surface

A and B are CO-DOMINANT A cell with BOTH an A and a B allele has BOTH “A” and “B” glycoproteins on its surface

BLOOD TYPES & ALLELES GENOTYPE PHENOTYPE (BLOOD TYPE) AA AO BB BO OO AB A A B B O

B and O see A as Different! IMMUNE SYSTEM ATTACKS! Body images modified from: A and AB see A as “like me” DONOR BLOOD

A and O see B as Different! IMMUNE SYSTEM ATTACKS! Body images modified from: B and AB see B as “like me” DONOR BLOOD

Body images modified from: YOU DON’T HAVE ANYTHING I DON’T HAVE! ____ can donate to EVERY BLOOD TYPE = _____________________ Nothing on surface to recognize as “NOT SELF” UNIVERSAL DONOR O DONOR BLOOD

A, B, and O see AB as Different! IMMUNE SYSTEM ATTACKS! Body images modified from: Only AB sees AB as “like me” DONOR BLOOD

Body image modified from: ______ can RECEIVE FROM EVERY BLOOD TYPE = ________________________ UNIVERSAL RECIPIENT ABAB AB can only GIVE to AB BUT...

BLOOD TYPE FREQUENCY IN USA A40% B10% AB4% O46%

ABO SYSTEM is NOT THE ONLY ONE Rh + Rh -

MOM is _____ & BABY is ____ OTHER BLOOD TYPES ____________________ IF: Image modified from: MOM is _____ & BABY is _____ Rh + Rh - NO PROBLEMS

Can be a ___________ IF: Mom is _____ Baby is _____ Image modified from: 1 st baby OK but few baby cells entering mom’s bloodstream put mom’s immune system on alert for + cells. Next + baby, mom’s immune system can attack baby as it is growing Mom given shot after 1 st birth prevents this Rh+ PROBLEM Rh -

Chromosomes that determine the sex of an organism = _________________ All other chromosomes = _________________ Sex chromosomes autosomes Humans have two sex chromosomes and _____ autosomes X y 44

SEX DETERMINATION XX = Xy = female male

Who decides? Mom can give X Dad can give X or y SO ____ determines sex of the baby. If dad gives X with mom’s X = girl If dad give y with mom’s X = boy X X X y X X y Dad

HEMOPHILIA CAUSE: Mutation in genes for __________________ carried ______ chromosome Blood clotting proteins are missing so person with this disorder can’t stop bleeding when injured; can ________________ from minor cuts or suffer internal bleeding from bruises or bumps. bleed to death Blood clotting proteins on X

HEMOPHILIA Treatment: Need ____________ of normal clotting proteins to stop bleeding _____________ in ______ because it is X-linked, but females with ______ recessive hemophilia alleles will also show the trait. 1 in 10,000 males has hemophilia injections males TWO More common

COLORBLINDNESS CAUSE: Mutation in one of three genes for _______________ carried on X chromosome Persons with this disorder have trouble distinguishing colors. _________________ colorblindness is most common Seen in 1 in 10 males 1 in 100 females Red-green Color vision

Males ONLY HAVE ONE X They either have the disorder DEFECTIVE NORMAL They are normal Or

FEMALES HAVE TWO X CHROMOSOMES Females have one normal gene that works. NORMALDEFECTIVE Females __________ defective recessive alleles to show the disorder need 2

The X chromosome in males... flies WITHOUT a copilot!... there’s NO BACK UP X to help them!

X-linked cross Dad is not colorblind Mom is colorblind What is the probability of having a colorblind boy? What is the probability of having a colorblind girl? XbXb XbXb XBXB y XB XbXB Xb XB XbXB Xb Xb yXb yXb yXb y All boys will be colorblind No girls will be colorblind

Girls with this genotype: X B X b don’t show the COLORBLIND trait They have a “backup” X. BUT.... They can pass the gene onto their offspring.

A heterozygous person who carries a recessive allele for a genetic disorder, but ________ show the trait themselves is called a _____________ CARRIER doesn’t