Human HeredityHuman Heredity

http://www.youtube.com/watch?v=hNMYV213xu0 – video on karyotypes

KARYOTYPE

Sordaria fimicola is a species of microscopic fungus. It is commonly found in the feces of herbivores. Sordaria fimicola is often used in introductory biology and mycology labs because it is easy to grow on nutrient agar in dish cultures. The genus Sordaria, closely related to Neurospora and Podospora, is a member of the large class Pyrenomycetes, or flask-fungi. The natural habitat of the three species of Sordaria that have been the principal subjects in genetic studies is dung of herbivorous animals. The species S. fimicola is common and worldwide in distribution. The species of Sordaria are similar morphologically, producing black perithecia containing asci with eight dark ascospores in a linear arrangement. These species share a number of characteristics that are advantageous for genetic studies. They all have a short life cycle, usually 7–12 days, and are easily grown in culture. Most species are self-fertile and each strain is isogenic. All kinds of mutants are easily induced and readily obtainable with particular ascospore color mutants. These visual mutants aid in tetrad analysis, especially in analysis of intragenic recombination.[1]

The most common form of S. fimicola is a dark brown. Certain mutants are grey or tan. A common experiment for an introductory biology lab class is to cross one of the mutant types with a wild type and observe the ratio of coloring in the offspring. This experiment illustrates the concepts of genetic inheritance in a haploid organism. The eight ascospores are produced inside an ascus. Sordaria squashes can give us information about crossing over during meiosis. If no crossing over then there is a 4:4 pattern. 4 black spores, and 4 tan spores all lined up. If crossing over does occur there is a 2:2:2:2 pattern visible, or a 2:4:2 pattern

What makes us human?What makes us human? To analyze chromosomes, cell biologist To analyze chromosomes, cell biologist

photograph cells in mitosis, when the photograph cells in mitosis, when the chromosomes are fully condensed and easy to chromosomes are fully condensed and easy to see.see.

Biologists then cut out the chromosomes and Biologists then cut out the chromosomes and group them together in pairs.group them together in pairs.

A picture of chromosomes arranged this way is A picture of chromosomes arranged this way is known as a KARYOTYPE.known as a KARYOTYPE.

Human Karyotype

What Can Our Chromosomes What Can Our Chromosomes Tell Us?Tell Us?

We can learn a lot by looking at We can learn a lot by looking at chromosomes! They can tell us everything chromosomes! They can tell us everything from the likelihood that an unborn baby will from the likelihood that an unborn baby will have a genetic disorder to whether a person have a genetic disorder to whether a person will be male or female. Scientists often will be male or female. Scientists often analyze chromosomes in prenatal testing and analyze chromosomes in prenatal testing and in diagnosing specific diseases. Follow the in diagnosing specific diseases. Follow the links to find out what we can learn from our links to find out what we can learn from our chromosomes.chromosomes.

Making a KaryotypeMaking a Karyotype A karyotype is an organized profile of a A karyotype is an organized profile of a

person's chromosomes. In a karyotype, person's chromosomes. In a karyotype, chromosomes are arranged and numbered chromosomes are arranged and numbered by size, from largest to smallest. This by size, from largest to smallest. This arrangement helps scientists quickly identify arrangement helps scientists quickly identify chromosomal alterations that may result in a chromosomal alterations that may result in a genetic disorder.genetic disorder.

Using Karyotypes to Predict Using Karyotypes to Predict Genetic DisordersGenetic Disorders

A normal human karyotype has 46 chromosomes: A normal human karyotype has 46 chromosomes: 22 pairs of autosomes and 2 sex chromosomes.22 pairs of autosomes and 2 sex chromosomes.

What happens when a person has something What happens when a person has something different, such as:different, such as:

Too many or too few chromosomes? Too many or too few chromosomes? Missing pieces of chromosomes? Missing pieces of chromosomes? Mixed up pieces of chromosomes?Mixed up pieces of chromosomes?

Too many or too few Too many or too few chromosomeschromosomes

To understand how our cells might end To understand how our cells might end up with too many or too few up with too many or too few chromosomes, we need to know how chromosomes, we need to know how the cells normally get 46 the cells normally get 46 chromosomes.chromosomes.

NondisjunctionNondisjunction

Homologous pair fails to separate in Meiosis I, or sister chromatids fail to separate in Meiosis II.

EngageEngageGenetic DisordersGenetic Disorders

Patau SyndromePatau Syndrome Edward SyndromeEdward Syndrome Klinfelter’s SyndromeKlinfelter’s Syndrome Turner SyndromeTurner Syndrome Super Male SyndromeSuper Male Syndrome Super Female SyndromeSuper Female Syndrome Down’s SyndromeDown’s Syndrome

Geneticists WantedGeneticists Wanted WANTED: Very intelligent scientists to WANTED: Very intelligent scientists to

help figure out what is wrong with these help figure out what is wrong with these children?children?

http://www.google.com/imgres?imgurl=http://www.biologycorner.com/worksheets/karyotype/karyotype-female.gif&imgrefurl=http://www.biologycorner.com/worksheets/karyotype/chromosomestudy-teacher.html&usg=__Tm3uv0lCTIgozDBpZuNOZmzTcd8=&h=720&w=650&sz=32&hl=en&start=12&um=1&itbs=1&tbnid=tzRP25VHPwJTqM:&tbnh=140&tbnw=126&prev=/images%3Fq%3Dkaryotype%26um%3D1%26hl%3Den%26sa%3DX%26tbs%3Disch:1

Karyotype printable worksheets for activity

Background:Background: Mr. and Mrs. Raider are deeply worried Mr. and Mrs. Raider are deeply worried

about their child who seems to be developing about their child who seems to be developing at a slower rate. They are concerned for the at a slower rate. They are concerned for the child’s health just like any other parent and child’s health just like any other parent and are asking you for help?are asking you for help?

What to hand inWhat to hand in:: You will be given a karyotype of the child to determine if You will be given a karyotype of the child to determine if

they have a genetic disorder and what kind.they have a genetic disorder and what kind. You will then write a dialogue that could have taken place You will then write a dialogue that could have taken place

between the geneticist and the parents of the child.between the geneticist and the parents of the child. Dialogue should be one pageDialogue should be one page Dialogue should include: Dialogue should include: -What the is the disease? / How this happened?-What the is the disease? / How this happened?-What are the symptoms?-What are the symptoms?-What is the life expectancy?-What is the life expectancy?-What they can do as parents?-What they can do as parents?-Is there a cure?-Is there a cure?

•Mothers in early 20s 1 in 1,500 births•Mothers over 35 1 in 70 births•Mothers over 45 1 in 25 births

47, XX or XY, +1347, XX or XY, +13

serious eye, brain, serious eye, brain, circulatory defects as circulatory defects as well as cleft palate. well as cleft palate. 1:5000 live births. 1:5000 live births. Children rarely live more Children rarely live more than a few months.than a few months.

Patau SyndromePatau Syndrome

Edward SyndromeEdward Syndrome

almost every organ system affected 1:10,000 live births. almost every organ system affected 1:10,000 live births. Children with full Trisomy 18 generally do not live more Children with full Trisomy 18 generally do not live more

than a few months. than a few months.

Klinefelter’s SyndromeKlinefelter’s Syndrome

Male sex organs; unusually small testes, sterile. Breast Male sex organs; unusually small testes, sterile. Breast enlargement and other feminine body characteristics. enlargement and other feminine body characteristics. Normal intelligence.Normal intelligence.

Turner SyndromeTurner Syndrome

the ONLY viable monosomythe ONLY viable monosomy

• 1 in 3,000 female births• Sterile females

Jacobs (XYY)Jacobs (XYY)

1 in 1000 male 1 in 1000 male birthsbirths

TallTall Lower mental Lower mental

abilityability Tendency for Tendency for

aggressivenessaggressiveness

Super Male and Super Male and Super FemaleSuper Female

- Has an XXX- Has an XXX- Fertile - Fertile females with females with normal normal intelligenceintelligence

Has an XYYHas an XYY- Tall male with heavy acne- Tall male with heavy acne- Some tendency to mental - Some tendency to mental retardationretardationAggressive tendencyAggressive tendency

Normal FemaleNormal Female

Normal MaleNormal Male

ExplainExplain

QuestionsQuestions

How many chromosomes come from your How many chromosomes come from your Father?Father?

How many chromosomes come from your How many chromosomes come from your Mother?Mother?

What are chromosome pairs 1-22 called?What are chromosome pairs 1-22 called? What is chromosome pair 23 called?What is chromosome pair 23 called?

DisordersDisorders

Name 3-4 diseases caused by a Name 3-4 diseases caused by a chromosomal abnormality.chromosomal abnormality.

What most often causes this abnormal What most often causes this abnormal number of chromosomes?number of chromosomes?

Terms to KnowTerms to Know

If either of these gametes unites with another during If either of these gametes unites with another during fertilization, the result is ________________ (any fertilization, the result is ________________ (any abnormal chromosome number)abnormal chromosome number)

A _____________cell has one extra chromosome (2n A _____________cell has one extra chromosome (2n +1). +1).

Down syndrome(trisomy 21), Klinefelters (XXY), Triple X Down syndrome(trisomy 21), Klinefelters (XXY), Triple X (XXX), Jacobs (XYY)(XXX), Jacobs (XYY)

A ___________ cell has one missing chromosome (2n A ___________ cell has one missing chromosome (2n - 1) Turners Syndrome- 1) Turners Syndrome

Aneuploidy

Trisomy

Monosomy

ElaborateElaborate

Draw pedigrees from the given problems.Draw pedigrees from the given problems.

EngageEngage

Sex-Linked Recessive – HemophiliaSex-Linked Recessive – Hemophilia““The Royal Disease” The Royal Disease”

Read the short story Read the short story Alexis: The Prince Who Had Hemophilia Alexis: The Prince Who Had Hemophilia ––by:-Kelley, Laureen A.by:-Kelley, Laureen A.

Set in the early 1900s, this is the story of the youngest child of Tsar Set in the early 1900s, this is the story of the youngest child of Tsar Nicholas II of Russia, last Tsar of Russia. The story includes how Nicholas II of Russia, last Tsar of Russia. The story includes how Alexis's hemophilia influenced the course of events in Russia that Alexis's hemophilia influenced the course of events in Russia that

led to the Russian Revolution led to the Russian Revolution

Some HistorySome History

Hemophilia has played an Hemophilia has played an important role in Europe's important role in Europe's historyhistory

The disease began to crop The disease began to crop up in Great Britain's Queen up in Great Britain's Queen Victoria’s childrenVictoria’s children

It became known as the It became known as the "Royal disease" because it "Royal disease" because it spread to the royal families spread to the royal families of Europe through Victoria's of Europe through Victoria's descendants descendants

How it SpreadHow it Spread

it spread through the it spread through the Royal Houses of Europe Royal Houses of Europe as monarchs arranged as monarchs arranged marriages to consolidate marriages to consolidate political alliances. political alliances.

We can trace the We can trace the appearance of appearance of hemophilia as it popped hemophilia as it popped up in Spain, Russia, and up in Spain, Russia, and Prussia by looking at Prussia by looking at the family tree. the family tree.

The Royal Family TreeThe Royal Family Tree

Queen Victoria's son Leopold's Family Queen Victoria's son Leopold's Family

His daughter, Alice of His daughter, Alice of Athlone, had one Athlone, had one hemophilic son (Rupert) hemophilic son (Rupert) and two other children -- and two other children -- a boy and a girl -- whose a boy and a girl -- whose status is unknown. status is unknown. – What is the chance that What is the chance that

her other son was her other son was hemophilic? hemophilic?

– What is the probability What is the probability that her daughter was a that her daughter was a carrier? hemophiliac? carrier? hemophiliac?

The Spanish ConnectionThe Spanish Connection Now for the Spanish connection: Now for the Spanish connection:

Victoria's youngest child, Victoria's youngest child, Beatrice, gave birth to one Beatrice, gave birth to one daughter, one normal son, and daughter, one normal son, and two hemophilic sons. two hemophilic sons.

Looking at the pedigree of the Looking at the pedigree of the royal family, identify which of royal family, identify which of Beatrice's children received the Beatrice's children received the hemophilic gene; why can you hemophilic gene; why can you make this conclusion? Notice that make this conclusion? Notice that Beatrice's daughter, Eugenie, Beatrice's daughter, Eugenie, married King Alfonso XIII of married King Alfonso XIII of Spain and had six children, one of Spain and had six children, one of whom was the father of Juan whom was the father of Juan Carlos, the current King of Spain.Carlos, the current King of Spain.

Would you predict that Juan Would you predict that Juan Carlos was normal, a carrier, or a Carlos was normal, a carrier, or a hemophilic? hemophilic?

German and Russian InfluencesGerman and Russian Influences