Incomplete Dominance & Codominance...Incomplete Dominance & Codominance Section 11-3 in Book. Review...

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Transcript of Incomplete Dominance & Codominance...Incomplete Dominance & Codominance Section 11-3 in Book. Review...

Page 1: Incomplete Dominance & Codominance...Incomplete Dominance & Codominance Section 11-3 in Book. Review of Mendel’s Principles
Page 2: Incomplete Dominance & Codominance...Incomplete Dominance & Codominance Section 11-3 in Book. Review of Mendel’s Principles

Incomplete Dominance &

Codominance

Section 11-3 in Book

Page 3: Incomplete Dominance & Codominance...Incomplete Dominance & Codominance Section 11-3 in Book. Review of Mendel’s Principles

Review of Mendel’s Principles

Genes are passed parents

offspring; get one allele from each

parent

During Meiosis, the alleles for a gene

segregate from each other.

During Meiosis, genes independently

assort with each other.

Page 4: Incomplete Dominance & Codominance...Incomplete Dominance & Codominance Section 11-3 in Book. Review of Mendel’s Principles

Exceptions to Mendel’s principles

POLYGENIC TRAIT

Sometimes, a trait is controlled

by many genes

Ex. Hair color, eye color, skin

color, Height

Page 5: Incomplete Dominance & Codominance...Incomplete Dominance & Codominance Section 11-3 in Book. Review of Mendel’s Principles

Exceptions to Mendel’s principles

MULTIPLE ALLELES

Sometimes, a trait has more

than 2 versions of a gene

Blood Type (A,B, O)

Page 6: Incomplete Dominance & Codominance...Incomplete Dominance & Codominance Section 11-3 in Book. Review of Mendel’s Principles

A blending between two phenotypes.

(One allele not completely dominant over

the other.). (2 alleles produce 3

phenotypes.)

Result: Heterozygous phenotype

somewhere in between homozygous

phenotype.

Incomplete Dominance

Page 7: Incomplete Dominance & Codominance...Incomplete Dominance & Codominance Section 11-3 in Book. Review of Mendel’s Principles

1. Incomplete Dominance

Examples:

Trait: Flower Color

Expressions: Red x

White Pink

RR= Red; RW= pink; WW=

white

straight hair, wavy, curly

Page 8: Incomplete Dominance & Codominance...Incomplete Dominance & Codominance Section 11-3 in Book. Review of Mendel’s Principles

Incomplete Dominance

Page 9: Incomplete Dominance & Codominance...Incomplete Dominance & Codominance Section 11-3 in Book. Review of Mendel’s Principles

Both phenotypes are fully expressed when

present.

A cross between organisms with two

different phenotypes produces offspring

with has both phenotypes of the parental

traits shown.

Codominance

Page 10: Incomplete Dominance & Codominance...Incomplete Dominance & Codominance Section 11-3 in Book. Review of Mendel’s Principles

2. Codominance

Both alleles

contribute to the

phenotype.

Example: In

come chickens

Black Chicken x

White

Speckled

Chicken

Page 11: Incomplete Dominance & Codominance...Incomplete Dominance & Codominance Section 11-3 in Book. Review of Mendel’s Principles

YOU tell me which type of

dominance…

Page 12: Incomplete Dominance & Codominance...Incomplete Dominance & Codominance Section 11-3 in Book. Review of Mendel’s Principles

YOU tell me which type of

dominance…

Codominance!

Page 13: Incomplete Dominance & Codominance...Incomplete Dominance & Codominance Section 11-3 in Book. Review of Mendel’s Principles

Type of

Dominance?

Page 14: Incomplete Dominance & Codominance...Incomplete Dominance & Codominance Section 11-3 in Book. Review of Mendel’s Principles

Type of

Dominance?

Incomplete

Dominance!

Page 15: Incomplete Dominance & Codominance...Incomplete Dominance & Codominance Section 11-3 in Book. Review of Mendel’s Principles

A Trait found on the X chromosome

Males only need 1 copy of a recessive

allele to to express a sex-linked trait trait

Red Green Colorblindness

Sex-Linked Trait