Complex Inheritance Patterns

Polygenic InheritanceIncomplete Dominance

CodominanceEnvironmental Factors

HeredityGenetics

Study of GENES

HeredityStudy of INHERITANCE PATTERNSPassing of traits from parents to offspring

Types of Complex InheritancePolygenic

Polygon: Multiple sidesPolygamy: Multiple marriagesPolytheism: Multiple godsPolygenic: Multiple GENES

Incomplete Dominance

Codominance

Environmental Factors

Polygenic InheritanceMultiple alleles (more than two options)Genes spread over different locations or

chromosomesMANY different combinations and mixesExamples:

Hair colorEye colorSkin color

Degrees of extremes (Dark to light, etc)

http://discovermagazine.com/2007/mar/eye-color-explained

Incomplete DominanceMIXINGSnapdragons:

Red (R1)

White(R2)

Pink(R1R2)

http://www.massasoit-bio.net/courses/136/136_courseassets/cummings_animations/snapdragon_crosses.html

Hair TypeStraight Hair: Homozygous: Incomplete

DominantCurly Hair: Homozygous: Incomplete

DominantWavy Hair: Heterozygous: A mix (Straight

and Curly)

Environmental FactorsSome genes are only expressed under certain

ENVIRONMENTAL CONDITIONSHydrangea Arctic Fox

http://www.interiorofficeplants.com/http:/www.interiorofficeplants.com/why-hydrangeas-are-different-colors/

Gender DeterminationAlligators, Tortoises and Turtles

Temperature changes the gender of offspring!

EXAMPLE:Female if HotMale if Cold

CodominanceMultiple alleles are DOMINANT over

othersBlood Type:

Dominant Types: A and BRecessive Types: O

AA or AO=Type ABB or BO=Type BAB=Type ABOO=Type O

http://www.google.com/imgres?um=1&hl=en&sa=N&rlz=1C1SNNT_enUS408US408&authuser=0&biw=1366&bih=667&tbm=isch&tbnid=8PsfdtfL6lbTEM:&imgrefurl=http://learn.genetics.utah.edu/content/begin/traits/blood/types.html&docid=MBMmwYaFY_nyrM&imgurl=http://learn.genetics.utah.edu/content/begin/traits/blood/images/ABObloodsystem.gif&w=489&h=285&ei=4cdWT46aLOnE2wX08cnlCQ&zoom=1&iact=hc&vpx=735&vpy=198&dur=2272&hovh=171&hovw=294&tx=158&ty=70&sig=115824390853095710786&page=1&tbnh=115&tbnw=197&start=0&ndsp=18&ved=1t:429,r:3,s:0

Rh+ and Rh-Simple dominance and recessiveness

Rh+ is the DOMINANT trait (R)Rh- is the RECESSIVE trait (r)

+ (Positive) simply means you carry Rh factor

Genotype Phenotype

RR (++) Positive

Rr (+-) Positive

Rr (--) negative

Want to know your blood type?Legally, we can’t do the lab anymore BUT…you can find out by Donating Blood

Here’s an example though…My blood type is O (I’m a universal donor)My brother is AB (He’s a universal acceptor)What are my parents?

(Let’s do this on the board…it’ll be easier)