Genetics Case Study:

The Royal Family

The Romanov Family •Romanov Empire included one-sixth of

the globe.

•Nicholas II became Czar of Russia in

1896

•Resentment against the Czar and

wealthy class begins at end of 19th

century.

Alexei • Born in 1904, Nicholas’s only son.

• Had hemophilia, a bleeding disorder.

• Had body guard with him at

all times to prevent accidents.

• Alexei had several internal

bleeding instances.

• These bleedings were stopped

after the prayers of the healer

Rasputin.

Rasputin

•Healer or Scoundrel????

•Alexandra (Alexei’s mom) called

Rasputin in to stop Alexei’s bleeding.

•Alexandra took Rasputin in as a

relative (which lowered public faith of

the Romanov family). His influence

on the Czar is arguable by historians.

•Assassinated by Russian aristocrats.

Rasputin

• Rasputin was drugged,

poisoned, and shot

before he died of

drowning in the Neva

river

End of the Empire

•July, 1918:

Russian Revolution

(Romanov’s

assassinated)

•Alexei’s body

missing from mass

grave found in

1990’s.

So what does this

have to do with

Genetics? Learn how to read a PEDIGREE.

Learn the inheritance pattern of HEMOPHILIA.

Sex-Linkage •Traits controlled by genes located on the sex

chromosomes are called sex-linked traits.

•The gene for a protein that helps blood clot is on the

X chromosome.

•If this gene is mutated (deletion, point mutation, etc),

it may cause HEMOPHILIA.

•Heterozygotes are carriers & may pass trait on to

children, but themselves appear normal.

•Other sex-linked traits are red-green colorblindness,

Duchenne muscular dystrophy, and Fragile X

syndrome.

Royal Family Pedigree

Pedigrees

• Each row represents a generation

• Genders represented by different shapes

• Affected individuals indicated by shading

• Carriers indicated by half shading

Reading a Pedigree

Sometimes, carriers

are indicated this way.

Pedigree Problems: Tips

• Recessive: trait usually skips a generation

• Dominant: trait shows up often

• Autosomal: trait seen in both genders

• Sex-linked: trait seen usually in 1 gender

Sample Pedigrees

Pedigree Practice

Dominant or recessive trait? Autosomal or sex-linked?

Pedigree Practice

Dominant or recessive trait? Autosomal or sex-linked?

Pedigree Practice

Dominant or recessive? Autosomal or Sex-linked?

Practice Problems

• http://www.yhc.edu/external/jasonb/previou

s_semesters/Bio103_Su2004/Links_of_Inte

rest/links_to_practice_pedigree_probs.htm

Create your own pedigree!

1. Draw your family tree like the pedigrees we’ve seen.

2. Decide on a trait, and shade the affected individuals. (see list of traits on next slide)

3. Show the trait through 3 generations in your family (grandparents, parents, and you and your siblings).

Dominant Recessive

Widow’s peak hairline Straight hairline

Tongue-rolling Can’t roll tongue

Free earlobes Attached earlobes

Can’t bend back 45° Hitchhiker’s thumb

Freckles No freckles

No chin cleft Chin cleft

Bent little finger Not bent

Oval face Square face

Morton’s Toe(2nd toe) Big Toe is tallest

Dark hair (brown/black) Blonde Hair

Not red hair Red Hair