Title: Human Heredity
1Human Heredity
http//www.youtube.com/watch?vhNMYV213xu0
video on karyotypes
2KARYOTYPE
3Sordaria 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 712 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 44 pattern.
4 black spores, and 4 tan spores all lined up. If
crossing over does occur there is a 2222
pattern visible, or a 242 pattern
4What makes us human?
- To analyze chromosomes, cell biologist photograph
cells in mitosis, when the chromosomes are fully
condensed and easy to see. - Biologists then cut out the chromosomes and
group them together in pairs. - A picture of chromosomes arranged this way is
known as a KARYOTYPE.
5Human Karyotype
6- What Can Our Chromosomes Tell Us?
- We can learn a lot by looking at chromosomes!
They can tell us everything from the likelihood
that an unborn baby will have a genetic disorder
to whether a person will be male or female.
Scientists often analyze chromosomes in prenatal
testing and in diagnosing specific diseases.
Follow the links to find out what we can learn
from our chromosomes.
7- Making a Karyotype
- A karyotype is an organized profile of a person's
chromosomes. In a karyotype, chromosomes are
arranged and numbered by size, from largest to
smallest. This arrangement helps scientists
quickly identify chromosomal alterations that may
result in a genetic disorder.
8- Using Karyotypes to Predict Genetic Disorders
- A normal human karyotype has 46 chromosomes 22
pairs of autosomes and 2 sex chromosomes. - What happens when a person has something
different, such as - Too many or too few chromosomes?
- Missing pieces of chromosomes?
- Mixed up pieces of chromosomes?
9- Too many or too few chromosomes
- To understand how our cells might end up with too
many or too few chromosomes, we need to know how
the cells normally get 46 chromosomes.
10Nondisjunction
Homologous pair fails to separate in Meiosis I,
or sister chromatids fail to separate in Meiosis
II.
11EngageGenetic Disorders
- Patau Syndrome
- Edward Syndrome
- Klinfelters Syndrome
- Turner Syndrome
- Super Male Syndrome
- Super Female Syndrome
- Downs Syndrome
12Geneticists Wanted
- WANTED Very intelligent scientists to help
figure out what is wrong with these children?
Karyotype printable worksheets for activity
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13Background
- Mr. and Mrs. Raider are deeply worried about
their child who seems to be developing at a
slower rate. They are concerned for the childs
health just like any other parent and are asking
you for help?
14What to hand in
- You will be given a karyotype of the child to
determine if they have a genetic disorder and
what kind. - You will then write a dialogue that could have
taken place between the geneticist and the
parents of the child. - Dialogue should be one page
- Dialogue should include
- -What the is the disease? / How this happened?
- -What are the symptoms?
- -What is the life expectancy?
- -What they can do as parents?
- -Is there a cure?
15- Mothers in early 20s 1 in 1,500 births
- Mothers over 35 1 in 70 births
- Mothers over 45 1 in 25 births
1647, XX or XY, 13
- serious eye, brain, circulatory defects as well
as cleft palate. 15000 live births. Children
rarely live more than a few months. - Patau Syndrome
17Edward Syndrome
- almost every organ system affected 110,000 live
births. Children with full Trisomy 18 generally
do not live more than a few months.
18Klinefelters Syndrome
- Male sex organs unusually small testes, sterile.
Breast enlargement and other feminine body
characteristics. Normal intelligence.
19Turner Syndrome
20- 1 in 3,000 female births
- Sterile females
21Jacobs (XYY)
- 1 in 1000 male births
- Tall
- Lower mental ability
- Tendency for aggressiveness
22Super Male and Super Female
- - Has an XXX- Fertile females with normal
intelligence
- Has an XYY- Tall male with heavy acne- Some
tendency to mental retardation - Aggressive tendency
23Normal Female
24Normal Male
25Explain
26Questions
- How many chromosomes come from your Father?
- How many chromosomes come from your Mother?
- What are chromosome pairs 1-22 called?
- What is chromosome pair 23 called?
27Disorders
- Name 3-4 diseases caused by a chromosomal
abnormality. - What most often causes this abnormal number of
chromosomes?
28Terms to Know
- If either of these gametes unites with another
during fertilization, the result is
________________ (any abnormal chromosome number) - A _____________cell has one extra chromosome (2n
1). - Down syndrome(trisomy 21), Klinefelters (XXY),
Triple X (XXX), Jacobs (XYY) - A ___________ cell has one missing chromosome (2n
- 1) Turners Syndrome
Aneuploidy
Trisomy
Monosomy
29Elaborate
- Draw pedigrees from the given problems.
30Engage
- Sex-Linked Recessive Hemophilia
- The Royal Disease
- Read the short story Alexis The Prince Who Had
Hemophilia by-Kelley, Laureen A.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 Alexis's
hemophilia influenced the course of events in
Russia that led to the Russian Revolution
31Some History
- Hemophilia has played an important role in
Europe's history - The disease began to crop up in Great Britain's
Queen Victorias children - It became known as the "Royal disease" because it
spread to the royal families of Europe through
Victoria's descendants
32How it Spread
- it spread through the Royal Houses of Europe as
monarchs arranged marriages to consolidate
political alliances. - We can trace the appearance of hemophilia as it
popped up in Spain, Russia, and Prussia by
looking at the family tree.
33The Royal Family Tree
34Queen Victoria's son Leopold's Family
- His daughter, Alice of Athlone, had one
hemophilic son (Rupert) and two other children --
a boy and a girl -- whose status is unknown. - What is the chance that her other son was
hemophilic? - What is the probability that her daughter was a
carrier? hemophiliac?
35The Spanish Connection
- Now for the Spanish connection Victoria's
youngest child, Beatrice, gave birth to one
daughter, one normal son, and two hemophilic
sons. - Looking at the pedigree of the royal family,
identify which of Beatrice's children received
the hemophilic gene why can you make this
conclusion? Notice that Beatrice's daughter,
Eugenie, married King Alfonso XIII of Spain and
had six children, one of whom was the father of
Juan Carlos, the current King of Spain. - Would you predict that Juan Carlos was normal, a
carrier, or a hemophilic?
36German and Russian Influences