It is a presentation about Non-mendelian genetics.

2. Who is the Father of
Genetics?

3. It refers to physical
appearance

4. It refers to genetic
make-up of an
organism

5. It the site on one
chromosome which
encodes a single protein
(influences one trait)

6. It is the DNA sequence
information that encodes a
different phenotype for a
particular gene (e.g. blue and
brown eyes encoded by one
gene that determines eye color)
Alleles

7. Having identical alleles
(one from each parent)
for a particular
characteristic.
Homozygous

8. Having two different
alleles for a particular
characteristic.
Heterozygous

9. By:
Mrs. Cyril A. Constantino

10. Parent 1
Parent 2

11. Non-Mendelian Genetics
Some traits don’t
follow the simple
dominant/recessive
rules that Mendel first
applied to genetics.

12. Non-Mendelian Genetics
Traits can be
controlled by more
than one gene.
Some alleles are
neither dominant nor
recessive.

13. Incomplete Dominance
One allele is not
completely dominant over
another.
The heterozygous
phenotype is a blending of
the two homozygous
phenotypes.

14. Incomplete Dominance
Example: four o’clock flowers
RR=red
WW=white
RW=pink (blending of the
two alleles)

15. Non-Mendelian Genetics
In incomplete dominance, it is only
the phenotype that is intermediate.
The red and white alleles remain
separate and distinct. Half the
gametes of the pink four o’clock carry
the allele for red and half carry the
allele for white. Therefore, the
genotypic ratio also becomes the
phenotypic ratio.

16. What color offspring would you get when you
cross a pure (homozygous) red snapdragon
with a pure white snapdragon?

17. Oddly Enough,
Neither Red Nor White
Snapdragon Flower
Color is controlled
by Incomplete
Dominance and a
new 3rd phenotype
is seen.

18. How does Incomplete Dominance
work?

19. Incomplete Dominance is a
Blending
Like Paint, the
RED Pigment
“MIXES” with the
WHITE to create
PINK-
FLOWERED
offspring

20. Incomplete Dominance can be seen in:
 Horses
( Chestnut x Cremello
 Palomino)
 Snapdragons
 Japanese Four O’
Clocks
Many flowers exhibit
incomplete dominance.

25. Allele Notation
HOW DO YOU WRITE OUT THE
GENOTYPE WHEN BOTH
ALLELES ARE DOMINANT?

26. You Must Use Different Letters
1. Choose different
letters to represent
each form (In this
case we’ll use “W” for
the white allele and
“R” for the Red
allele).
2. Remember to always
use CAPITAL letters.
This is incomplete
DOMINANCE.
RR WW
RW

27. So…The Cross Between Pure
Snapdragons Looks Like This
R R
W
W
RW RW
RW RW

28. Assignment:
1. Answer activity #2 : Mystery Bull
pp.33
2. Write the objectives, procedure and
questions and answer.
3. Write your work in a Bond paper
with border.

30. 1. One allele is not
completely dominant over
another.
2. The heterozygous
phenotype is a blending of
the two heterozygous
phenotypes.

31. 3. In incomplete
dominance, it is only
the genotype that is
intermediate.

32. 4. In Incomplete
Dominance there is a
new 3rd phenotype
seen.

33. What kind of genetics do these
organisms exhibit?

35. Determine the possible traits of
the calves if :
1.a red (RR) bull is mated with a
red (RR) cow 1
2.a white(WW) bull is mated
with a red(RR) cow 2
3.a roan bull(RW) is mated with
a red (RR) cow 3

36. 1. Will you be able to trace the father of
the calves? (1 point)
2. What are the possible phenotypes of
the calves for each cow? (3 point)
3. Do you think you will make Mang
Marcelino happy about the result of your
investigation? (1 point)
4.How are you going to explain it to him?
(3 point)
5.How would you apply what you have
learned to improve the breeds of livestock
in your area? (2 point)

38. Codominance
The same ratios as
Incomplete Dominance
occur:
A ratio of 1:2:1 for both
genotype and
phenotypes of a
monohybrid cross

Different Phenotype:
The two original
phenotypes are
combined to give a
SPOTTED or
MULTICOLORED
phenotype.
A cross between 2 tabbies
(the heterozygotes) results in
1 black : 2 tabbies : 1 tan cat

39. Codominance occurs in:
 Shorthorn Cow (White
+ Red)
 Blue Roosters (White +
Black)
 Human Blood Typing
(AB)
 Tabby Cats (Black and
Tan Fur)

40. Let’s Practice
Tabby cats exhibit codominance between tan and black
fur.
1. Can Tan Cat be heterozygous? Why or Why not?
2. If you mate a tabby with a black cat, what is the
phenotypic ratio of their offspring?
3. If the offspring of two cats are composed of 36
tabbies and 40 black cats, what are the parental
phenotypes and genotypes?

41. Notation for Codominance
1. Choose a letter to represent the gene.
2. Choose different letters to represent each of
the alleles.
3. Take the letters representing the alleles and
turn them into superscripts.
4. Combine the two. Remember to use capital
letters.

42. Writing out the Genotype
1. We’re going to use C to represent Coat Color of
a shorthorn cow.
2. Roan coat color is a combination of Red and
White hair so we’ll use “R” to represent Red and
“W” to represent white.
3. R  R and W  W
4. C + R  CR and C + W  CW
5. So a Red Cow would be CRCR , a white cow
would be CWCW, and a roan cow would be CRCW

43. Blood Typing
Human blood
typing is an
example of both
Codominance
and Multiple
Alleles
What does
Multiple Alleles
Mean?

44. The Alleles
 A and B blood types
are coded for by the
alleles:
IA and IB respectively.
These two alleles are
CODOMINANT.
 Blood type O is coded
for by the allele i and is
recessive to both IA
and IB (notice the
lower case letter).

45. Codominance
 Two alleles are both
expressed as a dominant
phenotype
 Coat color in cows
 RR: Red
 WW: White
 RW: Roan, white with red
spots (NOT pink!)

46. Codominance
Sickle-cell Disease
-common in people
of African descent
-sickled allele
causes hemoglobin
to change and red
blood cell forms a
crescent shape –
can’t carry oxygen
well

47. Codominance
Genotypes:
BN BN: normal blood cells
BNBS: normal blood cells and
sickled cells
BSBS: sickled blood cells

53. Alleles and Their Blood Types
i i O
IA IA
IA i
A
IB IB
IB i
B
IA IB AB

55. Multiple-Allele Series
Codominance
More than two choices of alleles are present
for a trait
ABO blood type has three alleles
ABO Blood types:
If both A and B are present, type is AB
Neither is recessive
Individuals can be type A, B, AB, or O
(recessive)

56. What is blood made up of?
 The red blood cells
 contain hemoglobin.
 Red blood cells transport O2 and CO2
to and from body tissues.
 The white blood cells
 fight infection.
 The platelets
 help the blood to clot
 The plasma
 Fluid which contains salts and various
kinds of proteins.

57. Determining Blood Type
Protein molecules found on the
surface of RBC’s and in the blood
plasma determine the blood type of
an individual.
Antigens are located on the surface
of the red blood cells
Antibodies are in the blood
plasma.

62. What are the different blood
groups?
 Blood group A (IA, IA ), (IA, i)
have A antigens on the surface of red
blood cells and B antibodies in blood
plasma.
 Blood group B (IB, IB ), (IB, i)
have B antigens on the surface of red
blood cells and A antibodies in blood
plasma.

63. What are the different blood
groups?
 Blood group AB (IA, IB )
have both A and B antigens on the
surface of red blood cells and no A or B
antibodies in blood plasma.
 Blood group O (i, i)
have neither A or B antigens on the
surface of red blood cells but have both A
and B antibodies in blood plasma.

64. Blood transfusions – who can
receive blood from whom?
 The transfusion will work if a person who is
going to receive blood has a blood group
that doesn't have any antibodies against the
donor blood's antigens.

66.  People with blood group O are called "universal
donors"
 People with blood group AB are called "universal
receivers."

67. Assignment:
Answer Activity #4: Boy or Girl?
p. 37
1 whole sheet of paper

68. 1. Mom has type A blood. Dad has
type AB blood. What possible
blood types could their children
inherit? (Show all possibilities).

69. 2. A wealthy elderly couple dies together in
an accident. A man comes forward, claiming
that he is their long lost son and is entitled to
their fortune. The couple were of blood types
AB and O. The man has type O blood. Could
he be the heir to the fortune? Show why or
why not.

70. 3. In rabbits, white coat color (CW) and
black coat color (CB) are codominant,
and both of these alleles are dominant
over albino (c); heterozygotes (CWCB)
are spotted.
Draw a Punnett Square that shows the
genotypes and phenotypes of the
offspring from a heterozygous black-
coated rabbit and a homozygous white-
coated rabbit?

71. 1. What kind of alleles must be present for a person to
have a blood type O blood?
a. Two O alleles c. One A allele and one O allele
b. Two A allele d. One B allele and one O allele
2. In what non-mendelian heredity does both alleles are
expressed equally in the phenotype of the heterozygote.
a. Codominance c. Multiple alleles
b. Incomplete dominance d. Complete dominance
3. It refers to cows with red hair and white blotches.
a. Mad cow c. calf
b. roan d. Pure cow

72. 4. Why is it that the offspring in table above
do not observe the dominant - recessive
relationship?
A. Due to incomplete dominance
B. Due to codominance
C. Due to complete dominance
D. Due to multiple alleles
5. A and B are codominant. If a person
receives an A allele and a B allele, their
blood type is _______.
a. Type A c. Type AB
b. Type B d. Type O

73. A. Given the blood types of the mother and the child,
identify the possible blood type of the father.
Mother’s
Blood
Type
Father’s
Blood
Type
Child’s
Blood
Type
A A,B,AB,O A
B A,AB AB
AB A,B,AB,O B
O O,A,B O

74. B. Show the possible alleles that can be found
in each offspring and write the blood type for
each offspring
POSSIBLE ALLELES FROM
FATHER
A(IA or i) B (IB or i) O
Possible
alleles
from
Mother
A A-IAIA/Iai
O-ii
A-IAi/
B-IBi/
AB-IAIB
O-ii,
A -IAi
B IAIB
O-ii
B-IBIB
Ibi
B-IBi
O-ii
O A-IAi
O-ii
B-IBi
O-ii
O-ii

75.  1. What blood type (or types) can be found in
an offspring if a mother has type A blood and
the father has type B Blood? AB, A, B, O
 2. What blood type (or types) can be found in
an offspring if a mother has type AB blood and
the father has type B blood? A, AB, B
 3. What blood type (or types) can be found in
an offspring if a mother has type O blood and
the father has type B blood? B, O
 Use the table to answer the following
questions, and list all possible blood types.

76. Rh Factor
 Refers to another antigen on red blood
cells
 Dominant trait is to have the antigen
 Rh+
 Recessive trait is not to have it
 Rh-
 A person with Rh- blood will produce
antibodies to Rh+ blood
 Can be a problem in pregnancy

77.  1. What blood type (or types) can be found in an
offspring if a mother has type A blood and the father
has type B blood?
 2. What blood type (or types) can be found in an
offspring if a mother has type AB blood and the
father has type B blood?
 3. What blood type (or types) can be found in an
offspring if a mother has type O blood and the
father has type B blood?

78.  Q1. What will be the sex of a child produced when an
egg is fertilized by a sperm that has a Y chromosome?
 Q2. What type of sperm must fertilize an egg to result
in a female child?
 Q 3. Based on this Punnett Square, what percent of
children would you expect to be male?
 Q 4. Which sex chromosome is present in both male
and female?
 Q5. Infer which sex chromosomes determines a
person’s sex.
 Q6. What are the other factors that may influence the
expression of human sexuality?

79. Aa X Aa
A a
A AA Aa
a Aa aa

80. X Y
X XX XY
X XX XY

81. XH Y
XH XHXH XHY
Xh XHXh XhY

82. XX – NORMAL FEMALE
XXh – CARRIER FEMALE
XY – NORMAL MALE
XhY – HEMOPHILIAC MALE

83. W w
W WW Ww
w Ww ww

84. F f
F FF Ff
f Ff ff

85. IA IB
i
I

86. Figure 7.6

90. Review
 Males have an X and a Y chromosome
 Females have two X chromosomes
 These chromosomes determine sex, so
genes located on these chromosomes
are known as sex-linked genes.

91.  The Y chromosome contains far fewer genes than the
X chromosome.

92.  The X and Y chromosomes are not
homologous – they do not contain
matching genes. Genes found only
in the X chromosomes are X-
linked, and genes found only in
the Y chromosomes are Y-linked.
Together, the X-linked and Y-
linked genes are called Sex-linked
genes.
•Disorders that are sex-linked are much more common in males,
because they would only need 1 recessive allele to have the trait;
rather than the two recessive alleles the females need.

93. Female Genotype Female Phenotype
XX NORMAL FEMALE
XXc CARRIER FEMALE
XcXc COLOR BLIND FEMALE
Male Genotype Male Phenotype
XY NORMAL MALE
XcY COLOR BLIND MALE

94. Female Genotype Female Phenotype
XX NORMAL FEMALE
XXh CARRIER FEMALE
XhXh HEMOPHILIAC FEMALE
Male Genotype Male Phenotype
XY NORMAL MALE
XhY HEMOPHILIAC MALE

95. Colorblindness
 Recessive
 Inability to see certain colors

96. Hemophilia
 Recessive trait
 Disorder where individuals are missing the normal
blood clotting protein.
 Uncontrolled bleeds from minor cuts or bruises.
 Female genotype:
 Male genotype:

97. Duchenne Muscular Dystrophy
 Recessive
 Progressive weakening and loss of skeletal muscle.
 Defective version of gene that codes for muscle
protein
 Female genotype:
 Male genotype:

98. KEY CONCEPTS:
Sex-linked traits are
inherited through the SEX
chromosomes.
Males have only one X
chromosome. Thus, if they
inherit the affected X, they
will have the disorder.

99. Females have two X
chromosomes. Therefore,
they can inherit/carry
the trait without being
affected if it acts in a
recessive manner.

100. X and Y chromosomes are not
homologous – they do not
contain matching genes. Genes
found only in the X-
chromosomes are X-linked, and
genes found only in the Y
chromosomes are Y-linked.
Together, the X-linked and Y-
linked genes are sex-linked genes.

101. Carriers refer to
individuals who are
heterozygous for the
inherited trait but do not
express it. They can pass
the allele of the trait to
their children

102.  EXAMPLES!!
 A woman who is heterozygous for normal vision
marries a man who is colorblind. What are the
chances of them having a son or daughter who is
colorblind?
**NOTE: You have to use X’s and Y’s, and read the
punnett square separately for boys and girls!**

103.  A woman who is homozygous for normal blood
clotting marries a man who has hemophilia. What
are the chances of them having a son or daughter
with hemophilia?