THE GENETICS OF HARRY POTTER

Bell ringer: Why is it incredibly rare for a woman to have color-blindness?

HARRY POTTER

Here’s the synopsis: http://www.youtube.com/watch?v=18cZhqdxk3E

MENDELIAN GENETICS

Some traits work simply, like Mendel predicted. They are either dominant or recessive. Red hair is one of these.

Red hair is recessive to all other hair colors.

THE WEASLEYS

Red hair runs in the Weasley family

THE WEASLEYS

Harry’s father had brown hair and Harry’s mother had red hair. What is Harry’s genotype? What are this father’s possible genotypes?

Harry marries Ginny, a redhead. What are the possible genotypes of their children?

HAGRID

Hagrid is a giant. Giantism is a genetic trait, however, it follows “incomplete dominance” rules.

Incomplete dominance is when alleles blend. Neither one is completely dominant over the other.

HAGRIDA normal wizard is about 5 to 6 feet tall. A giant is about 20 feet tall. Hagrid on the other hand is about 12 feet tall. What do you think his genoptype is?

Hagrid’s brother is 20 feet tall. What is his genotype? Can they be full brothers?

HARRY’S EYESHarry’s eyes are often referred to in the books. Harry has green eyes. His mother had green eyes and his father had hazel eyes.

Eye color is a case of codominance. Blue eyes (i) are recessive to both brown eyes (IB) and green (IG). When green and brown are both present, hazel eyes result.

Draw a punnett square to show the odds of Harry inheriting green eyes.

HARRY’S EYES

Using Harry’s genotype, determine the genotypes of his and Ginny’s children (Ginny has brown eyes).

MAGICAL ABILITY

In the magical world of Harry Potter, there are three kinds of wizarding abilities: Strong, normal and weak (also called squibs).

Magical ability is another incomplete trait. Those with normal magical ability have the genotype Mm, while strong wizards have MM.

MR. FILCH

Mr. Filch is the ground’s keeper at Hogwarts. He has hardly any magical ability. What is his genotype?

MAGICAL ABILITY

Something else happens with magical ability: a silencing gene.

Sometimes, a gene can be turned on and off. Another gene controls whether a person will express the gene. In Harry Potter’s world, some people have no magical ability because it is “silenced”.

HERMIONE

Hermione is a witch born to two muggle parents (people who have no magic). A gene silenced her parents magical abilities, but not hers because she has strong magical ability.

What is Hermione’s genotype?

HERMIONE

A gene for silencing magical ability is S. It is dominant. Anyone who gets at least one S will be a muggle. Since Hermione is a witch, what is her genotype?

HERMIONE

Hermione’s possible genotype is MMss, indicating her strong magical ability. What are possible genotypes of Hermione’s parents who are Muggles without the ability?

HARRY POTTER

Will Harry Potter and Ginny Weasley have magical children?

Harry’s cousin Dudley is a Muggle. Is it possible for him to have magical children? How?