Complex Genetics Sex-linked Co-Dominance Incomplete Dominance

What is Complex Genetics? So far, we’ve been learning about Mendalian Genetics the study of simple recessive and dominant traits Complex Genetics is the study of traits that are not simply 1 dominant or 1 recessive characteristic

The Four Types of Complex Genetics Sex-linked Genetics Co-Dominance Incomplete Dominance

What is Complex Genetics? So far, we’ve been learning about Mendalian Genetics the study of simple recessive and dominant traits Complex Genetics is the study of traits that are not simply 1 dominant or 1 recessive characteristic

The Four Types of Complex Genetics Dihibrid Crosses Sex-linked Genetics Co-Dominance Incomplete Dominance

DiHybrid Crosses A Dihybrid cross looks at TWO traits at once It works JUST like a monohybrid cross but it has more letters :)

How to Do a Dihybrid Cross There are 5 steps to figure out the probability of two traits 1. Look at each individual trait on its own and write out its genotype and phenotype 2. Write out the possible combinations Each combination should have have one letter from each of the traits 3. Put the parents’ genotype combinations on the outside of the square 4. Fill in the Punnett Square Determine the outcomes of the possible offspring

Now, Let’s Do One! Step One: Determine the phenotype and genotypes of each of the parents When Will Smith clasps his hands together, his left thumb is on top, which is a dominant trait (L). He also has a bent pinky finger (B), which is a dominant to a straight pinky finger. Will is heterozygous for his left thumb on top and heterozygous for a bent pinky. Jada Pinkett Smith is heterozygous for her left thumb on top, and is heterozygous for bent pinky fingers. Will’s Genotype__________ Phenotype________ Jada’s Genotype_________ Phenotype_________

Step Two Step Two: Write out all of the possible Combinations! Use the FOIL technique (first, outside, inside, last) Will’s Genotype_______________ Foil for the possible Combinations: Jada’s Genotype______________

Step Three Place the parent genotypes on the outside of the punnett square.

Step Four Fill out the Punnett Square!

Step Five: Determine the Possible Outcomes How do we figure out possibilities? Possibilities: BBLL BBLl BbLL BbLl Bbll bbLL bbLl bbll BL Bl bL bl BBLL BBLl BbLL BbLl Bbll bbLL bbLl bbll

Step Five Continued Phenotypes Possibilities Dominant Dominant Dominant Recessive Recessive Dominant Recessive Recessive BL Bl bL bl BBLL BBLl BbLL BbLl Bbll bbLL bbLl bbll

Sex-Linked Traits Some traits are only on your last two chromosomes, which are known as the Sex Chromosomes This means that gender affects the traits X-Linked traits: The trait is found only on an X chromosome. A girl will have 2 copies of the trait (one on each X chromosomes) A boy will have only ONE copy of the trait (they only have one X chromosome)

Sex Linked Carriers

Sex Linked Example Colorblindness is a X chromosome sex-linked disorder. Color-blindness is recessive. A Heterozygous female and a Colorblind male are worried about their future children... fill out a punnett square to figure out their possibilities: Mother: Genotype______ Phenotype______ Father: Genotype______ Phenotype______

Co-Dominance Codominance occurs when the trait of each allele shows up. Both alleles are equally dominant!! The common example of Codomiance: Blood Types!

Blood Types What are the different types of blood types? A B AB O

The Genotypes of the Four Blood Types?

Let’s Try Blood Typing! Beyonce and Jay Z have recently been blood typed. Beyonce has an AB blood type and JayZ is Heterozygous A. Complete the punnett Square: Beyonce: Genotype____ Jay Z: Genotype _____ Possible child Genotype _______ ________ Possible child Phenotypes ________

Incomplete Dominance Formal Definition: Incomplete dominance is a form of intermediate inheritance in which one allele for a specific trait is not completely dominant over the other allele. This results in a combined phenotype In Otherwords: How is this different from Co-Dominance?

Snap Dragon Flowers

Let’s Try Incomplete Dominance Tulips are beautiful flowers. Tall tulips have a genotype of TT and short tulips have a genotype of tt. Yet, some tulips are of medium length. Medium height tulips occur when a tulip is heterozygous for height. A homozygous tall tulip and a short tulip mate. What are their possible offspring? Tulip One: Genotype______ Phenotype:_______ Tulip Two: Genotype______ Phenotype:_______