GeneticsGenetics

the study of hereditythe study of heredityHeredity-the way in Heredity-the way in which traits of parents which traits of parents are passed on to are passed on to offspringoffspring

Austrian Monk considered to be the

“Father of Genetics” did experiments with peas

Gregor Mendel

Mendel studied 7 traits in peas.

Phenotype The way an ORGANISM

LOOKS

GenotypeTHE GENETIC MAKEUP OF

AN ORGANISM

What Did Mendel What Did Mendel Find?Find?

He discovered different laws He discovered different laws and rules that explain and rules that explain factors affecting heredity.factors affecting heredity.•Dominant/Recessive RuleDominant/Recessive Rule•Law of SegregationLaw of Segregation•Law of Independent Law of Independent

AssortmentAssortment

Dominant Traits

Characteristics you can always see if you have the genes.

Symbolized by a capital letter

Recessive Traits

Characteristics you cannot see if you have a dominant gene.

Symbolized by a lower case letter

Rule of Unit FactorsRule of Unit Factors

Each organism has two Each organism has two alleles for each traitalleles for each trait

–Alleles - different forms of Alleles - different forms of the same genethe same gene

Heterozygous & Heterozygous & HomozygousHomozygous

HeterozygousHeterozygous - if the two - if the two alleles for a trait are alleles for a trait are different different ((AaAa))

HomozygousHomozygous - if the two - if the two alleles for a trait are the alleles for a trait are the same same ((AAAA or or aaaa))

Law of SegregationLaw of Segregation Mendel noticed that some Mendel noticed that some

plants with a dominant trait plants with a dominant trait would have offspring with would have offspring with the dominant trait and the dominant trait and offspring with the recessive offspring with the recessive trait. trait.

Mendel figured the traits Mendel figured the traits must separate when the must separate when the plant passes them onplant passes them on

Law of Independent Law of Independent AssortmentAssortment

Mendel noticed the inheritance of Mendel noticed the inheritance of one trait did not affect the one trait did not affect the inheritance of another.inheritance of another.

Punnett Squares Punnett Squares

Help determine the possible Help determine the possible offspring from a genetic crossoffspring from a genetic cross

Harry Potter and the

Recessive Allele

Wizard Genetics

•Being a wizard or a muggle is all decided by genetics

•All humans including wizards receive one allele from each parent

Wizard Genetics

• The allele for magical ability is

recessive

• Wizards have the alleles mm

Wizard Genetics

• The allele for muggleness is M

• Muggles have the alleles Mm or MM

• M is dominant to m so you can only be a wizard if you have no M allele

The Malfoys

Lucius Malfoy (mm)

Narcissa Malfoy (mm)

Draco Malfoy( )The Malfoys are a ‘pure blood’ family; All their

ancestors are wizards so they must have the alleles mm

mm

Lily Potter (mm)

James Potter (mm)

Harry Potter (WW)

Both Harry’s parents had magical ability so they must both have been mm

They passed these alleles on to Harry

The Potters

mm

The Weasleys are pure blood wizards so they all have the alleles mm

Tom Riddle is a ‘half blood’.

His mother was a witch (mm) and his father was a muggle

Mom

Dad

Hermione is a powerful witch so she must be mm

Both her parents are muggles, what is their genotypes to each give Hermione an m

mmMom

Dad

What wizarding alleles would Ron and Hermione’s children have?

Ron (mm)

Hermione (mm)

Children

( )mm

What wizarding alleles would Ginny and Dudley’s children have?

If Dudley is Mm

Ginny mm

Dudley Mm

Children

WW or mMmM mm

What wizarding alleles would Ginny and Dudley’s children have?

If Dudley is MM

Ginny mm

Dudley MM

Children

WMm M

If Hermione’s parents were expecting a baby, what is the chance they will have another child

with wizard abilities?

If Hermione’s parents were expecting a baby, what is the chance they will have another

DAUGTER with wizard abilities?