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Non-Mendelian Non-Mendelian Genetics Genetics Inheritance patterns that Inheritance patterns that are neither dominant nor are neither dominant nor recessive recessive

Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

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Page 1: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

Non-Mendelian GeneticsNon-Mendelian Genetics

Inheritance patterns that are Inheritance patterns that are neither dominant nor recessiveneither dominant nor recessive

Page 2: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

Do Now:Do Now: Take out homework. Take out homework. Then…clear desks.Then…clear desks.

Homework:Homework: finish practice sheets finish practice sheets

Page 3: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

Genetics:Genetics: Dihybrid CrossesDihybrid Crosses

BbHh X bbhh (parents)BbHh X bbhh (parents)1.1. What gametes will each parent What gametes will each parent

produce?produce?

2.2. What will be the genotypes of their What will be the genotypes of their offspring?offspring?

3.3. What would be the phenotypes? What would be the phenotypes?

Page 4: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

Easter Egg GeneticsEaster Egg Genetics

PP=purplePP=purplepp=pinkpp=pinkPp=orangePp=orangeBB=blueBB=bluebb=yellowbb=yellowBb=greenBb=green

Bp=redBp=redBP=whiteBP=whitePb=yellow spottedPb=yellow spottedbp=white spottedbp=white spottedBlack=genetic Black=genetic

mutation!!!mutation!!!

An egg may be all purple, so it was PP crossed with PP. Or it may be orange and pink, meaning it was Ppxpp.

Page 5: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

In In Mendelian genetics (Complete Mendelian genetics (Complete dominance)dominance), there are only two possible , there are only two possible

phenotypes: dominant or recessivephenotypes: dominant or recessive

Tall plant X Short plant = Tall plantTall plant X Short plant = Tall plant

(TT) (tt) (Tt)(TT) (tt) (Tt)

Page 6: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

But, not all inheritance is based on the rules of Complete Dominance!!

Page 7: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

Other inheritance patterns include:Other inheritance patterns include:

1.1. Incomplete InheritanceIncomplete Inheritance

2.2. CodominanceCodominance

3.3. Multiple AllelesMultiple Alleles

4.4. Polygenic TraitsPolygenic Traits

5.5. Sex-linkedSex-linked

Page 8: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

1. Incomplete Inheritance: 1. Incomplete Inheritance: Blending traitsBlending traits

Neither trait is dominantNeither trait is dominantHybrids Hybrids BLENDBLEND to make a to make a

medium phenotypemedium phenotype

Red FlowerRed Flower X White Flower = X White Flower = PinkPink

(RR) (WW) (RW)(RR) (WW) (RW)

Page 9: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

Incomplete Inheritance ProblemIncomplete Inheritance Problem

What is the probability of pink flowers if What is the probability of pink flowers if pink flowers are bred with red flowers?pink flowers are bred with red flowers?

50% chance of Pink Flowers

Page 10: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

2. CoDominance: 2. CoDominance: Traits show up together as Traits show up together as

spots or stripesspots or stripes

Co = togetherCo = together

Black CowBlack Cow X White Cow = S X White Cow = Sppootttteedd CCooww

(BB) (WW) (BW)(BB) (WW) (BW)

Page 11: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

CoDominance ProblemCoDominance Problem

What are all the possible phenotypes What are all the possible phenotypes when two spotted cows are bred?when two spotted cows are bred?

Possible phenotypes are a black

cow, 2 spotted

cows, and a white cow

Page 12: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

Below are imaginary organisms. Note horn shape, leg length, fur color and tail shape. Now determine the type of inheritance of the four traits by examining the genotypes of

the parents and offspring.

Page 13: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

3. Multiple Alleles: 3. Multiple Alleles: More than 2 More than 2 types of alleles exist for a traittypes of alleles exist for a trait

Rabbits have more than 144 alleles for coat Rabbits have more than 144 alleles for coat color! color!

Page 14: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

The same allele can be dominant or

recessive depending on context::agouti > black > albinoagouti > black > albino

What will offspring look like if a What will offspring look like if a heterozygous agouti/black rabbit was heterozygous agouti/black rabbit was crossed with an albino rabbit?crossed with an albino rabbit?

Page 15: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

Blood type is determined by Blood type is determined by Multiple alleles and Co-dominanceMultiple alleles and Co-dominance

People have different blood types because of People have different blood types because of different carbohydrates on their surface. different carbohydrates on their surface.

Page 16: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

Blood Type Inheritance Rules:Blood Type Inheritance Rules:

1.1. A person with the A person with the IIAA allele will have A allele will have A carbohydrates. carbohydrates.

2.2. A person with the A person with the IIBB allele will have B allele will have B carbohydrates.carbohydrates.

3.3. A person with the A person with the recessive i allele will have no recessive i allele will have no carbohydratescarbohydrates..

4.4. Or a person with Or a person with both Iboth IAA and I and IBB alleles will have alleles will have both A and B carbohydrates both A and B carbohydrates on their cells.on their cells.

Page 17: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

Blood Type ProblemsBlood Type Problems

If a woman with AB blood has children with a man who has type O, what will be the possible genotypes of their children? What will be their blood types?

IA IB

ii

IA iIA i

IB iIB i

Cells Genotypes Blood types

IAi, IAIA Type A blood

IBi, IBIB Type B blood

IAIB Type AB blood

ii Type O blood

Page 18: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

Ever wonder why there are Ever wonder why there are ranges of skin colors, or eye ranges of skin colors, or eye

colors, or hair colors, or height?colors, or hair colors, or height?

Page 19: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

4. Polygenic Traits: Require the 4. Polygenic Traits: Require the interpretation of many genesinterpretation of many genes

Page 20: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

Parents:

Ll Mm Nn X Ll Mm NnLl Mm Nn X Ll Mm Nn

This also explains why a couple with This also explains why a couple with heterozygous genes heterozygous genes can have children can have children who look so different.who look so different.

This child received mostly dominant genes

This child received mostly recessive genes

Page 21: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

Why are some traits like color-Why are some traits like color-blindness, ALD and hemophilia blindness, ALD and hemophilia

found mostly in boys?found mostly in boys?

Page 22: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

5. Sex-linked: genes are found 5. Sex-linked: genes are found on the sex chromosomes (X or on the sex chromosomes (X or

Y)Y)Most of these traits are Most of these traits are recessiverecessive, the , the normal gene is dominantnormal gene is dominant

Page 23: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

Sex-linked inheritance rulesSex-linked inheritance rules

Heterozygous Females (XXHeterozygous Females (XXcc) ) are are carrierscarriers. . They do not show the trait, but carry a They do not show the trait, but carry a gene for the traitgene for the trait..

Homozygous Females (XHomozygous Females (XccXXcc) ) have the traithave the traitMales with the gene (XMales with the gene (XccY) Y) have the traithave the trait.—.—

They do not have another X to They do not have another X to counterbalance the affected genecounterbalance the affected gene

Page 24: Non-Mendelian Genetics Inheritance patterns that are neither dominant nor recessive

If a heterozgous woman with normal vision has children with a man who is colorblind, what are the chances that their children will be colorblind? Will any children be carriers of the trait?

Y

XcY

XY

Xc Y

Xc

X

XcXc

XXc

XcY

XY