A Family Tree

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Ch. 14 The Human Genome-Sec. 1 Human Heredity
A Family Tree
To understand how traits are passed on , a
pedigree diagram showing the family
relationships, is used. In a pedigree, a circle
s a female, a square s a male. A filled-in
circle or square shows that the individual has
the trait. The horizontal line that connects a
circle and a square s a marriage. The vertical
line(s) and brackets below are the child(ren) of
that couple.
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Ch. 14 The Human Genome-Sec. 1 Human Heredity
1. This pedigree shows the inheritance of
attached ear lobes. Which parent has attached ear
lobes? 2. How many children do the parents have?
Which child has attached ear lobes? 3. Which
child is married? Does this childs spouse have
attached ear lobes? Do any of this childs
children have attached ear lobes?
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Ch. 14 The Human Genome-Sec. 1 Human Heredity

• 141 Human Heredity
• Human Chromosomes
• 1. Karyotype
• a. autosomes
• b. sex chromo-
• somes
• Making a Karyotype activity
• http//learn.genetics.utah.edu/units/disorders/kar
  yotype/karyotype.cfm

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Ch. 14 The Human Genome-Sec. 1 Human Heredity
B. Human Traits- Click to see pedigree chart C.
Human Genes 1. Blood Group Genes Click to see
slide 2. Recessive Alleles 3. Dominant
Alleles 4. Codominant Alleles D. From Gene to
Molecule 1. Cystic Fibrosis Click here for
slide 2. Sickle Cell Disease Click here for
slide
Click here for concept map of these 3 alleles
Click button if you want to go directly to the
next section
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Click here to return to previous slide
A square represents a male.
A circle represents a female.
A horizontal line connecting a male and female
represents a marriage.
A vertical line and a bracket connect the parents
to their children.
A half-shaded circle or square indicates that a
person is a carrier of the trait.
A circle or square that is not shaded indicates
that a person neither expresses the trait nor is
a carrier of the trait.
A completely shaded circle or square indicates
that a person expresses the trait.
How to Read a Pedigree chart
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Ch. 14 The Human Genome-Sec. 1 Human Heredity
Human Blood Groups
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Ch. 14 The Human Genome-Sec. 1 Human Heredity
Autosomal Disorders
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Concept Map
caused by
Recessive alleles
Dominant alleles
Codominant alleles
Tay-Sachs disease
Huntingtons
Galacto- semia
Sickle cell
Albinism
Achondro- plasia
Hyper- choles- terolemia
Phenylketo-nuria
Cystic fibrosis
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Ch. 14 The Human Genome-Sec. 1 Human Heredity
Normal CFTR is a chloride ion channel in cell
membranes. Abnormal CFTR cannot be transported
to the cell membrane.
Chromosome 7
The most common allele that causes cystic
fibrosis is missing 3 DNA bases. As a result,
the amino acid phenylalanine is missing from the
CFTR protein.
The cells in the persons airways are unable to
transport chloride ions. As a result, the airways
become clogged with a thick mucus.
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20 of African Americans are carriers for sickle
cell disease. Children who receive a recessive
gene from each parent can become blind. Arms and
legs can become paralyzed or even die. Strokes
and heart attacks are common. Treatments are
available to decrease the complications of this
disease but there is no cure. Many African
Americans will ask to be tested to see if they
have one of these genes in their chromosomes.
Button takes you to next section.
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Ch. 14 The Human Genome-Section 2-Human
Chromosomes
Gender Benders
You may remember that in humans, the sperm cells
may carry an X chromosome or a Y chromosome,
while egg cells have only X chromosomes.
Sometimes, errors during meiosis in one of the
parents produce offspring with an abnormal number
of sex chromosomes.
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Ch. 14 The Human Genome-Section 2-Human
Chromosomes
1. On a sheet of paper, construct a Punnett
square for the following cross XX x XY. Fill
in the Punnett square. What does the Punnett
square represent? According to the Punnett
square, what percentage of the offspring from
this genetic cross will be males? What percentage
will be females? 2. On a sheet of paper,
construct a Punnett square for the following
cross XXX x XY. Fill in the Punnett
square. How is this Punnett square different from
the first one you constructed? What might have
caused this difference? 3. How do the offspring
in the two Punnett squares differ?
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Ch. 14 The Human Genome-Section 2-Human
Chromosomes

• 142 Human Chromosomes
• Human Genes and Chromosomes
• Click for nondisjunction slide
• B. Sex-Linked Genes
• 1. Colorblindness Click for punnett square slide
• 2. Hemophilia
• http//www.ygyh.org/hemo/whatisit.htm
• 3. Duchene Muscular Dystrophy
• http//www.ygyh.org/dmd/whatisit.htm

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Ch. 14 The Human Genome-Section 2-Human
Chromosomes
C. X-Chromosome Inactivation
The coloration of tortoiseshell cats is a visible
manifestation of X-inactivation. The "black" and
"orange" alleles of a fur coloration gene reside
on the X chromosome. For any given patch of fur,
the inactivation of an X chromosome that carries
one gene results in the fur color of the other,
active gene.
Click to go to next part of outline
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Ch. 14 The Human Genome-Section 2-Human
Chromosomes
D. Chromosomal Disorders 1. Down Syndrome- site
has interactive slide show of how this syndrome
occurs http//learn.genetics.utah.edu/units/disord
ers/karyotype/downsyndrome.cfm 2. Sex Chromosome
Disorders A. Turners site has interactive
slide show of how this syndrome
occurs http//learn.genetics.utah.edu/units/disord
ers/karyotype/turnersyndrome.cfm B.
Kleinfelters site has interactive slide show of
how this syndrome occurs http//learn.genetics.uta
h.edu/units/disorders/karyotype/klinefelter.cfm
Click to go to next part of outline
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Ch. 14 The Human Genome-Section 2-Human
Chromosomes
Homologous chromosomes fail to separate
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Ch. 14 The Human Genome-Section 2-Human
Chromosomes
Homologous chromosomes fail to separate
Meiosis I Nondisjunction
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Ch. 14 The Human Genome-Section 2-Human
Chromosomes
Homologous chromosomes fail to separate
Meiosis I Nondisjunction
Meiosis II
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Ch. 14 The Human Genome-Section 2-Human
Chromosomes
Daughter (normal vision)
How is colorblindness inherited???
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Ch. 14 The Human Genome-Section 2-Human
Chromosomes
Father (normal vision)
Normal vision
Click to return to outline
Colorblind
Male Female
Mother (carrier)
How is colorblindness inherited???
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Ch. 14 The Human Genome-Section 3-Human Molecular
Genetics
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143-Human Molecular Genetics A. Human DNA
Analysis 1. Testing for Alleles http//www.access
excellence.org/AE/AEPC/NIH/gene09.html
Different types of genetic tests are used to hunt
for abnormalities in whole chromosomes, in short
stretches of DNA within or near genes, and in the
protein products of genes.
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Ch. 14 The Human Genome-Section 3-Human Molecular
Genetics
2. DNA Fingerprinting-an on line interactive lab
(takes 45 minutes, may wish to assign for
home) http//www.pbs.org/wgbh/nova/sheppard/analy
ze.html DNA Game- quick look at how DNA
fingerprinting can solve a crime http//library.th
inkquest.org/C0125833/english/whodunit.php
Click to go to next slide
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Ch. 14 The Human Genome-Section 3-Human Molecular
Genetics
B. The Human Genome Project-This link is to the
HGP home page http//www.ornl.gov/sci/techresource
s/Human_Genome/home.shtml 1. Rapid Sequencing
2. Searching for Genes Click to go to slide 3.
A Breakthrough for Everyone public knowledge and
access. See above link.
Click to continue outline
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Ch. 14 The Human Genome-Section 3-Human Molecular
Genetics
Sequences can locate genes.
Intron
Click to return to outline
Start codon
Stop codon
Promoter
Insulin gene
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Ch. 14 The Human Genome-Section 3-Human Molecular
Genetics
C. Gene Therapy
Gene therapy using a virus. A new gene is
inserted into a virus, which is used to introduce
the modified DNA into a human cell. If the
treatment is successful, the new gene will make a
functional protein.
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Ch. 14 The Human Genome-Section 3-Human Molecular
Genetics
D. Ethical Issues in Human Genetics
Who owns and controls genetic information?
Who should have access to personal genetic
information, and how will it be used?
Do healthcare personnel properly counsel parents
about the risks and limitations of genetic
technology?
How does personal genetic information affect an
individual and society's perceptions of that
individual?
How does genomic information affect members of
minority communities?  
How reliable and useful is fetal genetic testing?
How do we prepare the public to make informed
choices?
How will genetic tests be evaluated and regulated
for accuracy, reliability, and utility?