Transcript 7.4 Human Genetics and Pedigrees

Set
CornellGenetics
Notes on pg.
7.4 up
Human
and Pedigrees
87
7.4
Human
Genetics and Pedigrees
2.1
Atoms,
Ions,
and Molecules
•Topic: 7.4 Human
Genetics and Pedigrees
KEY CONCEPT
A combination of methods
•Essential Questions:
is used to study human
1. NO EQ
genetics.
7.4 Human Genetics and Pedigrees
86
Autosomal Dominant Pedigree
Autosomal Recessive Pedigree
Autosomal Recessive Pedigree #2
7.4 Human Genetics and Pedigrees
KEY CONCEPT
A combination of methods is used to study human
genetics.
7.4 Human Genetics and Pedigrees
• The basic principles of genetics are the same in all sexually
reproducing organisms.
– Inheritance of many human
traits is complex
– Single-gene traits are
important in understanding
human genetics.
Ex: widow’s peak
Widow’s peak
7.4 Human Genetics and Pedigrees
A pedigree is a chart for tracing genes in a family.
• Phenotypes are used to infer genotypes
Please copy on Pg. 87
Pedigree Key:
Boxes
= males
Circles = females
Shaded
= they show the trait
White
= does not show trait
Half shaded
= carrier
(Carrier= Only for recessive disorders)
Offspring is dead=
7.4 Human Genetics and Pedigrees
1.
2.
3.
4.
How many females are in this family?
Pg. 86 top margin
How many carriers?
How many children were in generation two?
How many offspring in generation three are affected by the trait?
Generation 1
Generation 2
Generation 3
Generation 4
7.4 Human Genetics and Pedigrees
1. How many females are in this family? 11
2. How many carriers? 7
3. How many children were in generation two? 5
4.
How many offspring in generation three are affected by the trait? 2
Generation 1
Generation 2
Generation 3
Generation 4
7.4 Human Genetics and Pedigrees
In pedigrees that show Autosomal Dominant Traits/DisordersMany family members will be shaded
Widow’s peak
No Widow’s
peak
On
top of pg.
86, pleaseand
create
this pedigree and answer the
7.4the
Human
Genetics
Pedigrees
following questions. Always include GENOTYPE when possible:
Jamie and Joe married in 1912. Joe was homozygous dominant for a
Widow’s Peak, while Jamie did not have a Widow’s Peak. They had two
children: A son named Kyle and a daughter named Marie.
 Kyle married a woman who had no Widow’s Peak.
 Marie never married.
 Kyle and his wife had three children: Two boys and a girl.
• Do Kyle and Marie have Widow’s Peaks?
• What percent of Kyle’s children can we expect to have Widow’s
Peaks?
• What percent of Kyle’s children can we expect to have NO Widow’s
Peaks?
7.4 Human Genetics and Pedigrees
Joe
Jamie
WW
ww
Kyle
Marie
7.4 Human Genetics and Pedigrees
Joe
Jamie
WW
ww
Kyle
Marie
Ww
Ww
1. Yes, Kyle and Marie have Widow’s Peaks
WW x ww
• 100% Ww
7.4 Human Genetics and Pedigrees
ww
?
?
Joe
Jamie
WW
ww
Kyle
Marie
Ww
Ww
?
WW x ww
• 100% Ww
Ww x ww
• 50% Ww and 50% ww
1. Yes, Kyle and Marie have Widow’s Peaks
2. 50% should have Widow’s Peaks
3. 50% should have NO Widow’s Peaks
7.4 Human Genetics and Pedigrees
In pedigrees that show Autosomal Recessive Traits/Disorders only a
few organisms, will be shaded in.
• Only will show up if heterozygotes mate, may skip a few
generations before reappearing.
• REMEMBER: if it is an autosomal recessive disorders CARRIERS
will be present and must be half shaded in.
7.4 Human Genetics and Pedigrees
On the middle of pg.
86, Fill in the
genotypes of this
incomplete pedigree.
Shade if necessary.
Albinism is an autosomal
RECESSIVE disorder
aa
7.4 Human Genetics and Pedigrees
You need to complete
two Punnet sqs. to find
out the answer
Aa or AA?
aa
aa
aa
aa
7.4 Human Genetics and Pedigrees
Aa or AA?
aa
aa
aa
aa
AA x aa
• 100% Aa?
Aa x aa
• 50% Aa--50% aa
7.4 Human Genetics and Pedigrees
Aa or AA?
aa
aa
aa
aa
AA x aa
• 100% Aa?
Aa x aa
• 50% Aa--50% aa
7.4 Human Genetics and Pedigrees
Aa
aa
aa
aa
Aa
aa
Aa
Aa
7.4 Human Genetics and Pedigrees
Can use previous
Punnett Sq to
answer this
Aa or AA?
aa
aa
aa
Aa
Aa
aa
Aa
Aa
7.4 Human Genetics and Pedigrees
Aa
Aa
aa
aa
aa
Aa
Aa
aa
Aa
Aa
7.4 Human Genetics and Pedigrees
Aa
aa
AA x aa
• 100% Aa?
Aa x aa
• 50% Aa--50% aa
Aa or AA?
Aa
aa
aa
aa
Aa
Aa
Aa
Aa
Anyway to know for
sure?
7.4 Human Genetics and Pedigrees
Aa
aa
Aa or AA
?
Aa
Aa
aa
Aa
Aa
?
aa
aa
Aa
?
7.4 Human Genetics and Pedigrees
SHADE AS
NECESSARY
Aa
aa
Aa or AA
?
Aa
Aa
aa
Aa
Aa
?
aa
aa
Aa
?
Aa or AA
7.4 Human Genetics and Pedigrees
SHADE AS
NECESSARY
Aa
aa
Aa or AA
?
Aa
Aa
aa
Aa
Aa
?
aa
aa
Aa
?
Aa or AA
7.4 Human Genetics and Pedigrees
Bottom of Pg. 86
Mary and Joe were married in 1950.
Both Mary and Joe were carriers for a fatal recessive disorder
called Cystic Fibrosis.
They had three children: A son named Pete who was a carrier,
a son named Charles who was not a carrier and did not have
the disease, and a girl named Isabel who died from Cystic
Fibrosis.
Pete married a woman who was homozygous dominant. Pete
and his wife are worried about having a child with Cystic
Fibrosis.
Should they worry? What are the chances of any of their
children having Cystic Fibrosis? Carriers?
7.4 Human Genetics and Pedigrees
FF
?
Joe
Mary
Ff
Ff
Pete
Charles
Isabel
Ff
FF
ff
7.4 Human Genetics and Pedigrees
FF
Joe
Mary
Ff
Ff
Pete
Charles
Isabel
Ff
FF
ff
FF x Ff
• O%- No chance of
any of their children
having the disorder
• 50% will be carriers
They DO NOT need to
be worried about
having a child with CF
Set
CornellGenetics
Notes on pg.
7.4 up
Human
and Pedigrees
89
7.4Atoms,
Human
Genetics and Pedigrees:
2.1
Ions,
and Molecules
•Topic: 7.4 Human
Sex-linked traits
Genetics and Pedigrees
•Essential Questions:
1. NO EQ
7.4 Human Genetics and Pedigrees
Females can carry sex-linked genetic disorders.
• Males (XY) express all of their sex linked genes.
• Expression of the disorder depends on which parent carries
the allele and the sex of the child.
Y
X
7.4 Human Genetics and Pedigrees
• In pedigrees showing Sex-linked traits: More males will be
shaded in because they do not have another X to mask the
disorder Ex: Color blindness
males
females
7.4 Human Genetics and Pedigrees
XMXM= Normal
XMXm= carrier
XmXm= CB
XMY= Normal
XmY= CB
X-linked Color Blindness- Recessive
XmY
XmY
XMXm
On pg. 88, Fill in the
genotypes of this
incomplete pedigree.
Shade if necessary.
XMXm
XMXm
XMXm
XMY
?
XmY
XmY
XMXM or XMXm
7.4 Human Genetics and Pedigrees
• A karyotype is a picture of all chromosomes in a cell.
XY
7.4 Human Genetics and Pedigrees
• Karyotypes can show changes in chromosomes.
– deletion of part of a chromosome or loss of a
chromosome
– large changes in chromosomes
– extra chromosomes or duplication of part of a
chromosome
7.4 Human Genetics and Pedigrees
• In down syndrome a
person has an extra copy
of chromosome 21.
• In Klinefelter’s syndrome
a male has an extra X
(XXY).
7.4 Human Genetics and Pedigrees
Pedigree Practice Worksheet
7.4 Human Genetics and Pedigrees
• How many males?
• How many males have
hemophilia?
10
4
5
6
7
8
11
12
13
• How many females?
• How many females have
hemophilia?
9
14
15
16
7.4 Human Genetics and Pedigrees
• How many males? 8
• How many males have
hemophilia? 3
10
4
5
6
7
8
11
12
13
• How many females? 8
• How many females have
hemophilia? 2
9
14
15
16
7.4 Human Genetics and Pedigrees
• How many marriages are
there?
10
4
5
6
7
8
11
12
13
9
14
15
16
7.4 Human Genetics and Pedigrees
• How many marriages are
there? 3
10
4
5
6
7
8
11
12
13
9
14
15
16
7.4 Human Genetics and Pedigrees
• How many children did
the first couple have?
4
6
10
11
7
12
5
• How many children did
the third couple have?
8
• How many generations
are there?
13
9
14
15
• How many members in
16
the 4th generation?
7.4 Human Genetics and Pedigrees
• How many children did
the first couple have? 2
4
6
10
11
7
12
5
• How many children did
the third couple have? 7
8
• How many generations
are there? 4
13
9
14
15
• How many members in
16
the 4th generation? 7
7.4 Human Genetics and Pedigrees
4
10
Now the harder part…
Determine the GENOTYPES
for as many of the family
members as possible.
5
6
7
8
11
12
13
You can find all genotypes
except for one.
9
14
15
16
7.4 Human Genetics and Pedigrees
10
4
5
6
7
8
11
12
13
Fill in the OBVIOUS
genotypes first (the
affected individuals)
9
14
15
16
7.4 Human Genetics and Pedigrees
Fill in the OBVIOUS
genotypes first
• the affected individuals
• The non-affected males
XnXn
6
4
5
7
8
9
XnY
10
XnY
11
12
13
XnY
XnXn
14
15
16
7.4 Human Genetics and Pedigrees
Then start at the top, and
using Punnett Sqs.
Determine the possible
genotypes of the female
offspring in each
generation.
XnXn
4
5
XNY
6
7
8
XNY
10
XnY
11
You may need to complete
more than one!!!!!
9
XnY
12
13
XnY
XnXn
14
XNY
15
XNY
16
7.4 Human Genetics and Pedigrees
XnXn
XNY
6
XNXn
7
XnY
11
• 100%
XNXn
XNY
8
XNY
10
XnXn
5
4
XNXn
/
XNY
9
XnY
12
13
XnY
XnXn
14
XNY
15
XNY
16
7.4 Human Genetics and Pedigrees
XnXn
XNY
6
XNXn
7
XNY
8
XNY
10
XnY
11
• 50%
• 50%
5
4
XNXn
XNY
9
XnY
12
13
XnY
XnXn
14
XNY
15
XNY
16
/
XNXn
XNXn
XNXN
7.4 Human Genetics and Pedigrees
XnXn
XNY
5
4
XNXn
6
XNXn
7
XNY
10
XnY
11
?
XNY
XNXn or XNXN
8
9
XnY
12
13
XnY
XnXn
14
XNY
15
XNY
16
7.4 Human Genetics and Pedigrees
XnXn
XNY
5
4
XNXn
6
XNXn
7
?
XNY
8
9
XNY XNXn or XnY
XNXN
10
XnY
11
12
13
XnY
XnXn
14
XNY
15
XNY
16
You need to
complete 2 test
crosses to figure
out what mom is.
7.4 Human Genetics and Pedigrees
XnY
XnXn
XNY
XNXn
6
XNXn
7
?
XNY
8
9
XNY XNXn or XnY
XNXN
10
XnY
11
XNXn
and
XnY / XNXN
5
4
/
12
13
XnY
XnXn
14
XNY
15
XNY
16
7.4 Human Genetics and Pedigrees
XnY
XnXn
XNY
XNXn
6
XNXn
7
?
XNY
8
9
XNY XNXn or XnY
XNXN
10
XnY
11
XNXn
and
XnY / XNXN
5
4
/
12
13
XnY
XnXn
XNXn
14
XNY
15
XNY
16
7.4 Human Genetics and Pedigrees
XnXn
XNY
5
4
XNXn
6
SHADE THE
CARRIERS IN AS
NECESSARY
XNXn
7
?
XNY
8
9
XNY XNXn or XnY
XNXN
10
XnY
11
12
XNXn XnY
13
XnXn
XNXn
14
XNY
15
XNY
16
XNXn
7.4 Human Genetics and Pedigrees
XnXn
XNY
5
4
XNXn
6
Now answer the rest of
the questions.
XNXn
7
?
XNY
8
9
XNY XNXn or XnY
XNXN
10
XnY
11
12
13
XNXn
XnY
XnXn
XNXn
14
XNY
15
XNY
16
XNXn
7.4 Human Genetics and Pedigrees
Pedigree Worksheet
• Complete the back by yourself for homework
Part B
• NOT SEX-LINKED (no XX or XY)
• Determine if black fur or white fur is dominant or
recessive
• Use pencil in case you make mistakes
Part C
• Draw your own pedigree for the SEX-LINKED disorder
• Outline each shape following the color-coding key
7.4 Human Genetics and Pedigrees
Who Gets the Money
Purpose: To solve a mystery involving genetics
Background: Mr. and Mrs. John Jones dies in a tragic farm
accident when the tractor they were riding on rolled over in
a ditch. Authorities found one million dollars hidden in a
feed bin in the chicken coop. The couple is known to have
a son, from whom they are estranged. This man is sole heir
to the Jones fortune.
Procedure: Completes parts one, two, and three to find out
who gets the money!
7.4 Human Genetics and Pedigrees
Who Gets the Money
• Part I: Dihybrid Cross
• Part II: Punnett Squares
• Part II: Sex-linked Traits
Blood type:
Genotype
possibilities