Multiple alleles a gene inheritance pattern in which at least three unique alleles are present for one trait the three alleles may interact with each other using any other pattern DominantRecessive Incomplete Dominance Codominance etc ID: 585457
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Slide1
Multiple Alleles and Sex-Linked Patterns of InheritanceSlide2
Multiple alleles
a
gene inheritance pattern in which
at least
three unique alleles are present for one trait
the
three alleles may interact with each
other
using any other pattern (Dominant/Recessive, Incomplete Dominance, Codominance, etc.)
at
least
three phenotypes are
possibleSlide3
Multiple alleles
heterozygous
individuals’
phenotypes
must be determined using other inheritance patterns (Dominant/Recessive, Incomplete Dominance, Codominance, etc
.)
Example in humans
ABO blood type in humansSlide4
Multiple Alleles
& CodominanceSlide5
Multiple alleles
use capital and lowercase letters and/or superscript letters to show different alleles
T
A
= __________, T
B
= __________, t = __________
T
A
T
A
= __________,
T
A
t
= __________,
T
B
T
B
= __________,
T
B
t
= __________,
T
A
T
B
= __________,
tt
= __________Slide6
Multiple alleles
use capital and lowercase letters and/or superscript letters to show different alleles
T
A
= type A blood, T
B
= __________, t = __________
T
A
T
A
= __________,
T
A
t
= __________,
T
B
T
B
= __________,
T
B
t
= __________,
T
A
T
B
= __________,
tt
= __________Slide7
Multiple alleles
use capital and lowercase letters and/or superscript letters to show different alleles
T
A
= type A blood, T
B
= type B blood, t = __________
T
A
T
A
= __________,
T
A
t
= __________,
T
B
T
B
= __________,
T
B
t
= __________,
T
A
T
B
= __________,
tt
= __________Slide8
Multiple alleles
use capital and lowercase letters and/or superscript letters to show different alleles
T
A
= type A blood, T
B
= type B blood, t = type O blood
T
A
T
A
= __________,
T
A
t
= __________,
T
B
T
B
= __________,
T
B
t
= __________,
T
A
T
B
= __________,
tt
= __________Slide9
Multiple allelesSlide10
Multiple alleles
use capital and lowercase letters and/or superscript letters to show different alleles
T
A
= type A blood, T
B
= type B blood, t = type O blood
T
A
T
A
= __________,
T
A
t
= __________,
T
B
T
B
= __________,
T
B
t
= __________,
T
A
T
B
= __________,
tt
= __________Slide11
Multiple alleles
use capital and lowercase letters and/or superscript letters to show different alleles
T
A
= type A blood, T
B
= type B blood, t = type O blood
T
A
T
A
= type A blood,
T
A
t
= __________,
T
B
T
B
= __________,
T
B
t
= __________,
T
A
T
B
= __________,
tt
= __________Slide12
Multiple alleles
use capital and lowercase letters and/or superscript letters to show different alleles
T
A
= type A blood, T
B
= type B blood, t = type O blood
T
A
T
A
= type A blood,
T
A
t
= type A blood,
T
B
T
B
= __________,
T
B
t
= __________,
T
A
T
B
= __________,
tt
= __________Slide13
Multiple alleles
use capital and lowercase letters and/or superscript letters to show different alleles
T
A
= type A blood, T
B
= type B blood, t = type O blood
T
A
T
A
= type A blood,
T
A
t
= type A blood,
T
B
T
B
= type B blood,
T
B
t
= __________,
T
A
T
B
= __________,
tt
= __________Slide14
Multiple alleles
use capital and lowercase letters and/or superscript letters to show different alleles
T
A
= type A blood, T
B
= type B blood, t = type O blood
T
A
T
A
= type A blood,
T
A
t
= type A blood,
T
B
T
B
= type B blood,
T
B
t
= type B blood,
T
A
T
B
= __________,
tt
= __________Slide15
Multiple alleles
use capital and lowercase letters and/or superscript letters to show different alleles
T
A
= type A blood, T
B
= type B blood, t = type O blood
T
A
T
A
= type A blood,
T
A
t
= type A blood,
T
B
T
B
= type B blood,
T
B
t
= type B blood,
T
A
T
B
= type AB blood,
tt
= __________Slide16
Multiple alleles
use capital and lowercase letters and/or superscript letters to show different alleles
T
A
= type A blood, T
B
= type B blood, t = type O blood
T
A
T
A
= type A blood,
T
A
t
= type A blood,
T
B
T
B
= type B blood,
T
B
t
= type B blood,
T
A
T
B
= type AB blood,
tt
= type O bloodSlide17
Sex-linked
a
gene inheritance pattern seen when a trait is determined by a gene found on one of the sex chromosomes
many
traits are located only on the X chromosome
leads
to many recessive characteristics being common in males
males
only have one copy of the X
chromosomeSlide18
Sex-linked
Examples in humans
colorblindness, hemophilia (bleeder’s disease)Slide19
Sex-linked
must
use sex chromosomes as part of Punnett Square allele identification along with capital and lowercase letters and/or superscript letters to show different alleles
X
N
= X chromosome with a normal gene,
X
n
= X chromosome with a colorblind gene, Y = no gene
X
N
X
N
=
_______________,
X
N
X
n
=
________________,
X
n
X
n
= _______________
X
N
Y
=
_______________,
X
n
Y
=
_______________Slide20
Sex-linked
must
use sex chromosomes as part of Punnett Square allele identification along with capital and lowercase letters and/or superscript letters to show different alleles
X
N
= X chromosome with a normal gene,
X
n
= X chromosome with a colorblind gene, Y = no gene
X
N
X
N
=
normal female,
X
N
X
n
=
________________,
X
n
X
n
= _______________
X
N
Y
=
_______________,
X
n
Y
=
_______________Slide21
Sex-linked
must
use sex chromosomes as part of Punnett Square allele identification along with capital and lowercase letters and/or superscript letters to show different alleles
X
N
= X chromosome with a normal gene,
X
n
= X chromosome with a colorblind gene, Y = no gene
X
N
X
N
=
normal female,
X
N
X
n
=
normal female,
X
n
X
n
= _______________
X
N
Y
=
_______________,
X
n
Y
=
_______________Slide22
Sex-linked
must
use sex chromosomes as part of Punnett Square allele identification along with capital and lowercase letters and/or superscript letters to show different alleles
X
N
= X chromosome with a normal gene,
X
n
= X chromosome with a colorblind gene, Y = no gene
X
N
X
N
=
normal female,
X
N
X
n
=
normal female,
X
n
X
n
= colorblind female
X
N
Y
=
_______________,
X
n
Y
=
_______________Slide23
Sex-linked
must
use sex chromosomes as part of Punnett Square allele identification along with capital and lowercase letters and/or superscript letters to show different alleles
X
N
= X chromosome with a normal gene,
X
n
= X chromosome with a colorblind gene, Y = no gene
X
N
X
N
=
normal female,
X
N
X
n
=
normal female,
X
n
X
n
= colorblind female
X
N
Y
=
normal male,
X
n
Y
=
_______________Slide24
Sex-linked
must
use sex chromosomes as part of Punnett Square allele identification along with capital and lowercase letters and/or superscript letters to show different alleles
X
N
= X chromosome with a normal gene,
X
n
= X chromosome with a colorblind gene, Y = no gene
X
N
X
N
= normal female,
X
N
X
n
= normal female,
X
n
X
n
=
colorblind
female
X
N
Y
= normal male,
X
n
Y
= colorblind
maleSlide25
There are multiple alleles for human blood type. The allele for blood type A (T
A
) is
codominant
with the allele for blood type B (T
B
) while the allele for blood type O is recessive (t). If a heterozygous type A blood woman marries a heterozygous type B blood man, what is the likely phenotypic ratio of their kids
?
Identification of Alleles
T
A
=
type
A
blood
T
B
=
type B
blood
t = type O blood
Parent Genotype Identification
Woman:
T
A
t
Man:
T
B
tSlide26
Punnett Square
T
A
t
T
B
t
There are multiple alleles for human blood type. The allele for blood type A (T
A
) is
codominant
with the allele for blood type B (T
B
) while the allele for blood type O is recessive (t). If a heterozygous type A blood woman marries a heterozygous type B blood man, what is the likely phenotypic ratio of their kids?Slide27
Punnett Square
T
A
T
B
T
A
t
T
B
t
There are multiple alleles for human blood type. The allele for blood type A (T
A
) is
codominant
with the allele for blood type B (T
B
) while the allele for blood type O is recessive (t). If a heterozygous type A blood woman marries a heterozygous type B blood man, what is the likely phenotypic ratio of their kids?Slide28
Punnett Square
T
A
T
B
T
B
t
T
A
t
T
B
t
There are multiple alleles for human blood type. The allele for blood type A (T
A
) is
codominant
with the allele for blood type B (T
B
) while the allele for blood type O is recessive (t). If a heterozygous type A blood woman marries a heterozygous type B blood man, what is the likely phenotypic ratio of their kids?Slide29
Punnett Square
T
A
T
B
T
B
t
T
A
t
T
A
t
T
B
t
There are multiple alleles for human blood type. The allele for blood type A (T
A
) is
codominant
with the allele for blood type B (T
B
) while the allele for blood type O is recessive (t). If a heterozygous type A blood woman marries a heterozygous type B blood man, what is the likely phenotypic ratio of their kids?Slide30
Punnett Square
T
A
T
B
T
B
t
T
A
t
tt
T
A
t
T
B
t
There are multiple alleles for human blood type. The allele for blood type A (T
A
) is
codominant
with the allele for blood type B (T
B
) while the allele for blood type O is recessive (t). If a heterozygous type A blood woman marries a heterozygous type B blood man, what is the likely phenotypic ratio of their kids?Slide31
There are multiple alleles for human blood type. The allele for blood type A (T
A
) is
codominant
with the allele for blood type B (T
B
) while the allele for blood type O is recessive (t). If a heterozygous type A blood woman marries a heterozygous type B blood man, what is the likely phenotypic ratio of their kids?
Phenotypic Ratio of Children
1 type AB blood : 1 type A blood : 1 type B blood : 1 type O bloodSlide32
If
a child has Type B blood and his father has Type AB blood, what would his mother’s genotype be if her phenotype was Type A blood
?
Identification of Alleles
T
A
=
type
A
blood
T
B
=
type B
blood
t = type O blood
Parent Genotype Identification
Woman: T
A
_?_
Man
:
T
A
T
BSlide33
Punnett Square
T
A
?
T
A
T
B
If a child has Type B blood and his father has Type AB blood, what would his mother’s genotype be if her phenotype was Type A blood?Slide34
Punnett Square
T
A
T
A
T
A
?
T
A
T
B
If a child has Type B blood and his father has Type AB blood, what would his mother’s genotype be if her phenotype was Type A blood?Slide35
Punnett Square
T
A
T
A
T
A
T
A
?
T
A
T
B
If a child has Type B blood and his father has Type AB blood, what would his mother’s genotype be if her phenotype was Type A blood?Slide36
Punnett Square
T
A
T
A
T
A
T
A
T
B
T
A
?
T
A
T
B
If a child has Type B blood and his father has Type AB blood, what would his mother’s genotype be if her phenotype was Type A blood?Slide37
Punnett Square
T
A
T
A
T
A
T
A
T
B
T
B
T
A
?
T
A
T
B
If a child has Type B blood and his father has Type AB blood, what would his mother’s genotype be if her phenotype was Type A blood?Slide38
Where is the Type B child?Slide39
Punnett Square
T
A
T
A
T
A
T
A
T
B
T
B
T
A
?
T
A
T
B
If a child has Type B blood and his father has Type AB blood, what would his mother’s genotype be if her phenotype was Type A blood?Slide40
Punnett Square
T
A
T
A
T
A
t
T
A
T
B
T
B
t
T
A
t
T
A
T
B
If a child has Type B blood and his father has Type AB blood, what would his mother’s genotype be if her phenotype was Type A blood?Slide41
If a child has Type B blood and his father has Type AB blood, what would his mother’s genotype be if her phenotype was Type A blood?
Mother’s Genotype
T
A
tSlide42
In humans normal color vision is due to a dominant allele. Red-green color deficiency is due to its recessive allele. This gene is present on the X chromosome and thus is sex-linked. A homozygous normal female has children with a color deficient male. What is the probability that one of their
daughters
is color deficient? What is the probability that one of their
sons
is color deficient?
Identification of Alleles
X
N
= normal vision
X
n
= color deficient vision
Y = no gene
Parent Genotype Identification
Woman
:
X
N
X
N
Man
:
X
n
YSlide43
Punnett Square
X
N
X
N
X
n
Y
In humans normal color vision is due to a dominant allele. Red-green color deficiency is due to its recessive allele. This gene is present on the X chromosome and thus is sex-linked. A homozygous normal female has children with a color deficient male. What is the probability that one of their
daughters
is color deficient? What is the probability that one of their
sons
is color deficient?Slide44
Punnett Square
X
N
X
n
X
N
X
N
X
n
Y
In humans normal color vision is due to a dominant allele. Red-green color deficiency is due to its recessive allele. This gene is present on the X chromosome and thus is sex-linked. A homozygous normal female has children with a color deficient male. What is the probability that one of their
daughters
is color deficient? What is the probability that one of their
sons
is color deficient?Slide45
Punnett Square
X
N
X
n
X
N
X
n
X
N
X
N
X
n
Y
In humans normal color vision is due to a dominant allele. Red-green color deficiency is due to its recessive allele. This gene is present on the X chromosome and thus is sex-linked. A homozygous normal female has children with a color deficient male. What is the probability that one of their
daughters
is color deficient? What is the probability that one of their
sons
is color deficient?Slide46
Punnett Square
X
N
X
n
X
N
X
n
X
N
Y
X
N
X
N
X
n
Y
In humans normal color vision is due to a dominant allele. Red-green color deficiency is due to its recessive allele. This gene is present on the X chromosome and thus is sex-linked. A homozygous normal female has children with a color deficient male. What is the probability that one of their
daughters
is color deficient? What is the probability that one of their
sons
is color deficient?Slide47
Punnett Square
X
N
X
n
X
N
X
n
X
N
Y
X
N
Y
X
N
X
N
X
n
Y
In humans normal color vision is due to a dominant allele. Red-green color deficiency is due to its recessive allele. This gene is present on the X chromosome and thus is sex-linked. A homozygous normal female has children with a color deficient male. What is the probability that one of their
daughters
is color deficient? What is the probability that one of their
sons
is color deficient?Slide48
In humans normal color vision is due to a dominant allele. Red-green color deficiency is due to its recessive allele. This gene is present on the X chromosome and thus is sex-linked. A homozygous normal female has children with a color deficient male. What is the probability that one of their
daughters
is color deficient? What is the probability that one of their
sons
is color deficient?
Color Deficient Daughter Probability
0/4
Color Deficient
Son ProbabilitySlide49
But are there really 4 daughters?Slide50
In humans normal color vision is due to a dominant allele. Red-green color deficiency is due to its recessive allele. This gene is present on the X chromosome and thus is sex-linked. A homozygous normal female has children with a color deficient male. What is the probability that one of their
daughters
is color deficient? What is the probability that one of their
sons
is color deficient?
Color Deficient Daughter Probability
0/4
0/2
Color Deficient
Son ProbabilitySlide51
Remember to simplify fractions!Slide52
In humans normal color vision is due to a dominant allele. Red-green color deficiency is due to its recessive allele. This gene is present on the X chromosome and thus is sex-linked. A homozygous normal female has children with a color deficient male. What is the probability that one of their
daughters
is color deficient? What is the probability that one of their
sons
is color deficient?
Color Deficient Daughter Probability
0/4
0/2
0
Color Deficient
Son Probability
0Slide53
In
humans hemophilia (bleeders disease), is due to a recessive X linked allele. The normal condition (your blood clots) is due to the dominant allele. Show the phenotypic ratios possible in a cross between a heterozygous female and a normal
male.
Identification of Alleles
X
N
= normal blood clotting
X
n
= hemophilia
Y = no gene
Parent Genotype Identification
Woman
:
X
N
X
n
Man
:
X
N
YSlide54
Punnett Square
X
N
X
n
X
N
Y
In humans hemophilia (bleeders disease), is due to a recessive X linked allele. The normal condition (your blood clots) is due to the dominant allele. Show the phenotypic ratios possible in a cross between a heterozygous female and a normal male.Slide55
Punnett Square
X
N
X
N
X
N
X
n
X
N
Y
In humans hemophilia (bleeders disease), is due to a recessive X linked allele. The normal condition (your blood clots) is due to the dominant allele. Show the phenotypic ratios possible in a cross between a heterozygous female and a normal male.Slide56
Punnett Square
X
N
X
N
X
N
X
n
X
N
X
n
X
N
Y
In humans hemophilia (bleeders disease), is due to a recessive X linked allele. The normal condition (your blood clots) is due to the dominant allele. Show the phenotypic ratios possible in a cross between a heterozygous female and a normal male.Slide57
Punnett Square
X
N
X
N
X
N
X
n
X
N
Y
X
N
X
n
X
N
Y
In humans hemophilia (bleeders disease), is due to a recessive X linked allele. The normal condition (your blood clots) is due to the dominant allele. Show the phenotypic ratios possible in a cross between a heterozygous female and a normal male.Slide58
Punnett Square
X
N
X
N
X
N
X
n
X
N
Y
X
n
Y
X
N
X
n
X
N
Y
In humans hemophilia (bleeders disease), is due to a recessive X linked allele. The normal condition (your blood clots) is due to the dominant allele. Show the phenotypic ratios possible in a cross between a heterozygous female and a normal male.Slide59
In humans hemophilia (bleeders disease), is due to a recessive X linked allele. The normal condition (your blood clots) is due to the dominant allele. Show the phenotypic ratios possible in a cross between a heterozygous female and a normal male.
Phenotypic Ratios
(include differences for females and males)
2 normal females : 1 normal male : 1 hemophilic male