aabhay bhansali Pacific Coaching Class, Ner Jainam Bhansali Sanyam Bhansali

1. 9/13/2018 1Pacific Coaching Classes, Ner
प्रस्तुत कतता
B.Sc., M.Sc. {Evs.Sci.}, B.Ed.
अह िंसत परमो धमा

2. Theodor Boveri
Born 12 October 1862
Bamberg, Bavaria
Died 15 October 1915 (aged 53)
Wurzburg, Bavaria
Nationality German
Known for Embryonic development
Boveri-Sutton
chromosome theory
Centrosome
Scientific career
Fields Genetics, Cell biology
Walter Sutton
Born 5 April 1877
Utica, NY
Died 10 November 1916 (age 39)
Kansas City, KS
Nationality American
Alma mater University of Kansas, Columbia
University
Known for Boveri-Sutton chromosome
theory
Surgical improvements
Scientific career
Fields Genetics, Medicine

3. 1

4. Q-: Explain the chromosomal theory of inheritance?or Explain the chromosomal theory ? (3 M)
“Chromosomal theory of Inheritance” was put forth by Walter Sutton &
Theodor Bovery in 1904.
It is the theory of Genetics which identify Chromosomes as carrier of genetic material.
It state that,
1) Gametes (Ova & Sperms) carry all the heredity characters.
2) Nucleus of the gametes contain Chromosomes which carry
all the heredity character.
3) Chromosomes always found in pairs in diploid or somatic
cells.
4) During gamete formation, homologous chromosomes
segregates independently at meiosis. thus each gametes
haploid in nature.
5) During fertilization, the union of sperms and egg restore the
diploid nature of chromosomes.

5. 2

6. Heredity-:
Heredity can be defined as the inheritance or
transmission of characters from one generation to
the next generation.However,
There are some differences between parents
and offspring as well as their siblings are commonly
referred as “Variations”.The branch of science which deals with study of
mechanisms of heredity as well as causes of variation is

7. 3

8. Cell
Prokaryotic
Eukaryotic
 Irregular folded mass of
genetic materials called
Nucleoid.
 Chromosome is single & made
up of Circular DNA.
 Cells without nucleus or
with primitive nucleus.
 Cells with true nucleus.
 Shows typical chromosomes.
 With histone proteins.
All the individuals of same
species have similar number of
Additional circular DNA
found in prokaryotes called
“Plasmids”. It is capable of
independent existence.

9. Prokaryotic cell Eukaryotic cell

10. 4

11. We will discuss about,
 General Characteristics of Chromosomes
 Number of chromosomes
 Size of Chromosomes
 Shape of Chromosomes
 Structure of Chromosomes
 Types of Chromosomes
 Structure of X & Y Chromosomes.
F

13. General Characteristics of Chromosomes
1) Chromosomes are
responsible for
inheritance of
characters.
2) They regulate the
protein synthesis & thus
help in cell division and
cell growth.
3) They control cell
metabolism by directing
the synthesis of enzymes.
Que-: What are the function of chromosomes?(2M)

14. 5) Chromosomes replicates to produce exact
copies of themselves which are passed on to
daughter cell.
4) Sex chromosomes are essential for determination
of sex.
General Characteristics of Chromosomes
Que-: What are the function of chromosomes?(2M)

15. 5

16. Number of chromosomes
E.g. In human being,
each somatic or body cell contain two sets of chromosomes (Diploid, 2n= 46) &
gametes contains one set of chromosomes (Haploid, n=23).
Out of 23 pairs of chromosomes , 22 pairs are autosomes and one pair is Sex
Chromosomes.

18. 6

19. Size of Chromosomes
1)The size of chromosomes varies
from species to species.
2) It varies from 0.1 um to 33 um
in length & 0.2 to 2 um in
thickness. This is apparent
during metaphase.
Que-: What is the size of chromosomes?

20. 7

21. Shape of Chromosomes
 The shape varies according to the
stages of cell division.
 In interphase, chromosomes are in
the form of chromatin network while,
In metaphase, they are show
maximum condensation and appear
short and thick.

22. 8

23.  A metaphasic chromosomes
has two identical halves called
Sister chromatids.
 Each chromatids is in turn
made up of sub-chromatids
called Chromonemata.
(singular- chromonemata).
 The chromatids lie side by
side and held together at one
point called the centromere.
Que-: Describe the structure & types of Chromosomes?
Sketch & label the structure of chromosomes ?

24.  The centromere is also called the primary
constriction.
 During cell division the spindle fiber are
attached at the centromere.
 Besides the primary constriction,
additional narrow areas called secondary
constriction are present.
 Some of the secondary constriction are
called nucleolar organizers because they are
necessary for formation of nucleolus.

25.  The part of the chromosomes
beyond the nucleolar organizers is
short, spherical and is called
satellite. The tip of the chromosome is
called Telomere.
 It has a unique property that
it prevents the ends of the
chromosomes from sticking
together but attaches to the
nuclear envelope.
 The surface of chromosomes bears
number of small swellings called

26. 9

28. According to position of
centromere, chromosomes
are classified in to
following types
Types of Chromosomes

29. Types of Chromosomes
Metacentric Chromosomes

30. Types of Chromosomes
Sub-Metacentric Chromosomes

31. Types of Chromosomes
Acro-centric Chromosomes

32. Types of Chromosomes
Telo-centric Chromosomes

33. 10

34.  X chromosome is longer than Y chromosomes.
 X chromosome contain large amount of
euchromatin & small amount of heterochromatin.
 The euchromatin contains large amount of DNA or
Genes.
Structure of X & Y Chromosomes.
 Y chromosome contain small amount of
euchromatin and large amount of hetero chromatin.
Describe the structure of sex chromosomes?(3M)(Oct-14)

35. Structure of X & Y Chromosomes.
 It has (Y-chromkosome) less DNA hence genetically
less active.
 X & Y chromosomes shows homologous & non
homologous regions.
 Homologous regions shows similar genes while non
homologous regions shows dissimilar genes.
Describe the structure of sex chromosomes?(3M)(Oct-14)

36.  Crossing over occurs only in homologous regions.
 Non homologous regions of X chromosome
contains more genes than that of non homologous
region of Y chromosome.
 Non Homologous regions of X chromosom
contains X linked genes while non homologous
regions of Y chromosomes contain Y linked genes.
Structure of X & Y Chromosomes.
Describe the structure of sex chromosomes?(3M)(Oct-14)

37. 11

38. Distinguish between the X & Y chromosomes?
1.The X chromosomes is
larger than the Y
chromosomes.
2.The X chromosomes
contain large amount of
chromatin. The
chromosomes contain
small amount of hetero
chromatin.
1.The Y-chromosomes is
shorter than X
chromosomes.
2.The Y chromosomes
contain small amount of
euchromatin. The Y
chromosomes contain
the large amount of
heterochromatin.
X-Chromosomes Y-Chromosomes

39. 3.In X-chromosomes,
there is larger amount
of DNA or Active
Genes.
4. Non Homologous
region of X
chromosomes contain
more genes.
5.X-linked genes are
present on the X
chromosomes.
X-Chromosomes Y-Chromosomes
3.In Y-chromosomes,
there is lesser amount
of DNA or active
genes.
4.Non-homologous
region of Y
chromosomes contains
lesser genes.
5.Y-linked or holandric
genes are present on
the Y chromosomes.

40. X-Chromosomes Y-Chromosomes
6.The X-chromosomes is
present in double dose
in female & in a single
dose in male cells.
6.The Y-Chromosomes
present in single dose
in male while absent
in female cell.
In Female In Male

41. 12

42. Linkage.
The tendency of genes to inherit
together is called as ‘Linkage’.
All the genes on a chromosomes
are said to be linked to one
another & belong to same linkage
group.
No. of linkage group of a particular
species equal to its haploid no.
chromosomes or no. of pairs of
chromosomes. E.g. Number of linkage
group in human being is 23.
 Linkage group can be
broken by crossing over
during meiosis to form a new
combination of genes.
Que-: Write a note on linkage?

43. Kind of linkages-:
Linkage
Complete Linkage
In-complete Linkage
Que-: What are the different type of linkage?

44. Kind of linkages-:
The linked genes which are
closely located in the
chromosomes & do not
separate, & able to inherited
together commonly called as
Completely Linked Genes.
The phenomenon of their
inheritance is called ‘Complete
linkage’.
Complete linkage-:
The linked genes which are
widely located on the
chromosomes & may
separate by crossing over
are called incompletely
linked genes.
Incomplete Linkage-:
The phenomenon of their
inheritance is called
‘Incomplete linkage’.

45. 13

46. Sex linked inheritance or Sex linkages-:
Sex linked inheritance
In-complete Sex linkage
Complete sex linkage
The transmission of body characters from parents to
offspring along with sex chromosomes is called ‘Sex linked
inheritance or Sex Linkage’.
Que-: Write a note on sex-linked inheritance?
What is sex linkage? Explain the inheritance of color blindness & Haemophilia with suitable chart?

47. Sex linked inheritance or Sex linkages-:
Complete sex linkage-:Incomplete sex Linkage-:
 Incompletely sex
linked genes are
located on
homologous region
of X & Y
chromosomes.
 Completely sex
linked genes are
located on the non
homologous region of
X & Y chromosomes.
<- completely sex linked
genes
Que-: Describe types of sex linkage?

48. Sex linked inheritance or Sex linkages-:
Complete sex linkage-:Incomplete sex Linkage-:
They do not inherit
together because
crossing over occurs
in these region.
(Loosely linked).
They inherit
together as crossing
over does not occurs
in these regions.
(tightly linked).
Que-: Describe types of sex linkage?

49. Sex linked inheritance or Sex linkages-:
Complete sex linkage-:Incomplete sex Linkage-:
Hence these genes
are called incompletely
sex-linked genes &
their mode of
inheritance is called
‘Incomplete sex linked
inheritance or
incomplete sex linkage’.
 Hence these genes
are called completely
sex-linked genes &
their mode of
inheritance is called
complete sex-linked
inheritance or
complete sex linkage.
Que-: Describe types of sex linkage?

50. Sex linked inheritance or Sex linkages-:
Complete sex linkage-:Incomplete sex Linkage-:
 E.g. Total color
blindness, Retinitis
pigmentosa, Nephritis
etc.
E.g. Red green color
blindness,
Haemophilia, Myopia
etc.
Que-: Write a note on sex-linked inheritance?

52. Born September 25, 1866
Died December 4, 1945 (aged 79)
Nationality United States
Awards Nobel Prize in Physiology or
Medicine (1933)
Copley Medal (1939)
signature
Some things are better
done than described.
Known for Establishing Drosophila
melanogaster as a major model
organism in genetics; Linked genes
Education University of Kentucky, Johns
Hopkins University
Thomas Hunt Morgan

53. (i) It is easily available over ripe Mango/Banana fruits where it
feeds over yeast cells present over the fruit surface,
(ii) The flies can be reared inside bottles having yeast culture
over medium containing cream of wheat, molasses and agar.
(iii) A new generation can be raised within 2 weeks with single
mating producing hundreds of individuals,
Thomas Hunt Morgan (the father of experimental
genetics) selected fruit-fly Drosophila melanogaster (the
Jackpot of Genetics) as experimental materials though it is
small sized (2mm size) because of following advantages of
Drosophila over Pea.

54. (iv) The animals can be temporarily in-activated with
ether and examined by hand lens/dissection
microscope.
(v) Female is distinguishable from male by its
larger size and ovipositor at the rear end.
(vi) The animals possess four pairs of chromosomes of
different sizes. The male fly possesses XY sex
chromosomes while the female has XX chromosomes. Y
chromosome is hooked and easily distinguished.
(viii) Breeding Drosophila is quite cheap. Further, it can be done
throughout the year.
(vii) Polytene chromosomes occur in salivary glands of
larva which can indicate any type of abnormality.

55. Que-: Describe the experiment performed by Morgans?(3 M)
One day in 1910, American geneticist Thomas Hunt
Morgan peered through a hand lens at a male fruit fly, and he
noticed it didn't look right.
Instead of having the
normally brilliant red eyes of wild-
type Drosophila melanogaster, this
fly had white eyes.
so, Morgan chose to do a simple breeding analysis to find out
more about white eyes.

56. The members of the resulting F1 generation had all red
eyes, but Morgan suspected that the white-eye trait was still
present yet unexpressed in this hybrid generation, like
a recessive trait would be.
To test this idea, Morgan then crossed males and
females from the F1generation to investigate for a pattern
of white eye reoccurrence.
Upon doing so, he observed a 3:1 ratio of red eyes to
white eyes in the F2 generation.
Thus, he first performed a test cross between the
white-eyed male fly and several purebred, red-eyed females
to see whether white eyes might also occur in the next
generation.

57. Cross
Outcome
Expected Phenotypes Observed Phenotypes
P1 Red ♀ × P1 White ♂ F1 = All Red F1 = All Red*
F1 Red ♀ × F1 Red ♂
75% Red ♀ and ♂
25% White ♀ and ♂
50% Red ♀
25% Red ♂
25% White ♂
Strangely, however, all of Morgan's white-eyed F2 flies
were male, just like their grandfather—there were no white-
eyed females at all!
Sir Morgan knew that, Genes were located on X-Chromosomes,
thus he stated as

58. 1) When the two genes in a Di-hybrid cross were situated on
the same chromosomes, the proportion of parental gene
combination is much higher than the non parental type
due to linkage of two genes. The non parental gene
combination is due to Recombination.
2) When two genes are grouped on the same
chromosomes, some genes were very tightly linked
while other are loosely linked.
E.g.
The genes for white eye and yellow body were tightly linked &
shows 1.3% recombination.
The genes for white eye and miniature wing were loosely
linked & show 37.2 % recombination.

60. 13

61. Color blindness
 Color blindness is a sex linked disease in which the
person cannot able to differ between Red & Green color.
Both color appears as grey
color to infected person.
The color blindness is caused by
recessive genes which prevents the
proper formation of color sensitive
cells in the retina necessary for
distinction of red and green.
Que-: What is color blindness ? Explain its inheritance with the help of suitable chart?

62.  The genes for normal vision (Dominent) & color
blindness (Recessive) are located on non homologous
region of X-chromosomes but their alleles are absent in
Y-chromosomes.
 If genes for normal vision is represented by XC
and genes for color blindness by Xc then
genotypes of different individuals can be
represented as follows
Sex Normal Colorblind Carrier
Male XCY XcY ------
Female XCXC XcXc XCXc

63.  The inheritance of color blindness can be studied
with the help[ of following example
1) If a color blind male (XcY) marries female with
normal vision (XCXC) then
• all the offspring will have normal
vision.
• The sons will have normal vision but
daughter will be carriers for the
disease.
• The carrier have normal vision.

64. Color Blind Male Normal Female
XcY XCXC
Xc Y XC XC
XCXc XCYXCXc XCY
XCXc = Carrier female XCY = Normal malePhenotypically all normal.
Parents-:
Phenotype
Genotype
Gametes
F1 Generation
Meiosis 

65. Color Blind Male Normal Female
X X
Xc
Y
X X
Parent
Gametes
Xc Y
X Y
X YXc X Xc X
F1 Generation
Carrier Females ( 50% ) Normal Males ( 50% )

66. 2) If a carrier female (XCXc) marries a male with
normal vision (XCY) then
 All daughter will have normal vision
of which half of them will be carriers
for the disease.
 Half of the sons will be color blind
while remaining half will have
normal vision.

67. Carrier Female Normal male
XCXc XCY
XC Xc XC Y
XCXC XcXCXCY XcY
Parents-:
Phenotype
Genotype
Gametes
F2 Generation
Meiosis 
Normal
Female
Normal
Male
Carrier
Female
Colorblind
Male

68. Normal
Male
Carrier
Female
Xc X
X
Y
Xc X
Parent
Gametes
X Y
Xc
Y
X YX Xc X X
Female
Carrier (25%)
Normal
Female (25%)
Color blind
Male (25%)
Normal Male
(25%)

69. From the above example, it is clear that color
blind father transmits the disease to his grand son
through his carrier daughter.
The inheritance of character from the
father to his grand son through his
daughter is called criss – cross inheritance.
Give Scientific reasons: Human female is reffered as carrier of color blindness.?

70. 9

71. Haemophilia
Def-: The haemophilia is a blood related hereditary
disorder in which the blood of sufferer fails to clot or very
slowly clotted.
The persons which carries the recessive genes for
haemophilia has deficiency of clotting factor (factor vii
or ix) in blood, so minor injuries cause continuous
bleeding. Hence it is called bleeder’s disease.
The genes for normal clotting (dominent) &
Haemophilia (recessive) are located on non-homologous
region of X- chromosomes but their alleles are absent in
Y-chromosomes.
What is haemophilia? Explain its inheriatance with the help of suitable chart?

72. Sex Normal Haemophilic Carriers
Male XHY XhY ------
Female XHXH XhXh XHXh
Haemophilia
If genes for normal clotting of blood is
represented by XH and gene for haemophilia by
xh, then genotype of different individuals can
be represented as follows:

73. Haemophilia
The inheritance of haemophilia can be studied with the help of following
examples-
1)If a Haemophilic male (XhY) marries with normal
female (XHXH), then
all the offspring will have normal clotting of blood.
The son will have normal clotting of blood but
daughter will be carriers for the disease.
The carriers have normal clotting of blood.
2) If a carrier female (XHXh) marries a normal male (XHY), then
all daughter will have normal clotting of blood but half of
them will be carriers for the disease.
Half the son will be Haemophilic while remaining have
normal clotting of blood. `

74. 1) If a Haemophilic male (XhY) marries with
normal female (XHXH), then
 all the offspring will have normal clotting
of blood.
 The son will have normal clotting of blood
but daughter will be carriers for the
disease.
 The carriers have normal clotting of blood.
Haemophilia

75. Haemophilic Male Normal Female
XhY XHXH
Xh Y XH XH
XHXh XHYXHXh XHY
XHXh = Carrier female XCY = Normal malePhenotypically all normal.
Parents-:
Phenotype
Genotype
Gametes
F1 Generation
Meiosis 
Haemophilia

76. Haemophilia
2) If a carrier female (XHXh) marries a
normal male (XHY), then
all daughter will have normal clotting
of blood but half of them will be
carriers for the disease.
Half the son will be Haemophilic while
remaining have normal clotting of
blood.

77. Carrier Female Normal Male
XHXh XHY
XH Xh XH Y
XHXH XhYXHXH XHY
XHXh = Carrier female XCY = Normal malePhenotypically all normal.
Parents-:
Phenotype
Genotype
Gametes
F1 Generation
Meiosis 
Haemophilia

78. Haemophilia

79. 9

80. Explain sex determination in human beings& Birds?
Or
Explain the mechanism of sex determination in human beings?
(Oct-15, Mar-16)
Or
Explain the mechanism of sex determination in birds? (Jul-16)
Describe the sex determination in honeybee? Or with the help of
chart, explain the method of sex determination in honeybee?
(Mar-14)(3M)
Drone of honeybee shows haploid number of chromosomes?
Illustrate?
Sex Determination

81. Sex Determination
 In human being, The chromosomal mechanism of
sex determination is of XX-Xy type.
 In Humans, the nucleus of each cell contain 46
chromosomes or 23 pairs of chromosomes.
 Out of these, 22 pairs are autosomes
(responsible for determination of body characters)
and 1 pair is of sex chromosomes (responsible for
determination of sex).
 In female, two homo-morhic chromosomes are XX while
in male, two heteromorphic sex chromosomes are XY.

82.  Thus the genotype of male & female is as
Female: 46 chromo. = 44 autosomes + XX sex chromo.
Male : 46 chromo. = 44 autosomes + XY sex chromo.
Sex Determination

83. Mechanism of sex determination
 During gamete formation, the diploid germ cells in
the testes and ovaries undergo meiosis to produce
haploid gametes (Sperms and Eggs).
 The homologous chromosomes separate and
enter in to two different gametes.
 The human male is
Heterogametic & produces
two types of sperms as
1) 22A + X 2) 22A + Y
 The human female
is homogametic &
produces only one
type of eggs containing
(22A+ X).

84. During fertilization,
Mechanism of sex determination
 If X containing sperm fuse with egg having
X-chromosomes then, resulting offspring
with XX-chromosomes is a female.
 If Y containing sperm fuses with egg
having X-chromosomes then, resulting
offspring with XY-chromosome is a male.

85. Male Female
XY XX
X Y X X
XX XYXX XY
XX = femaleXY = Male
Parents-:
Phenotype
Genotype
Gametes
F1 Generation
Meiosis 
Mechanism of sex determination in Human
Possibility of 50 % Male & 50% Female offspring

86. This indicates,
The sex of child depends on the type of sperms fuses with
it and thus “The father is responsible for sex of the child and
not the mother.”
 Chromosomal mechanism of sex determination is called
“Heterogamesis”.
 It may be male heterogamety or female heterogamety.
Pacific Coaching Classes, Ner

87. What is sex ratio? Why is the number of female declining in India?

88.  In honey bees,
sex is determined by no. of sets of
chromosomes received by an individuals. Such type of sex
determination is called ‘Haplo-Diploid Sex Determination’.
The fertilized egg develop as a female offspring (may be queen
or worker). It shows diploid number (2n=32) of chromosomes.
An unfertilized egg develop as a Male (Drone) by
means of parthenogenesis. Thus the Drone have haploid
number (1n=16) of chromosomes. The Drone are capable to
produce sperms by mitosis.
Haplo-Diploid system of sex determination.

89. Haplo-Diploid system of sex determination.
Female Male
Meiosis Mitosis
Haploid (n=16) Haploid (n=16) Haploid(n=16)
Diploid (2n=32) FemaleMale (1n=16)
Diploid=2n=32 Haploid=1n=16
Parthenogenesis

90. Mechanism of sex determination in Birds
 In birds, sex determination is of ZW-ZZ type.
 In this type,
Males are homogametic and have ZZ Sex
chromosomes &
Female are heterogametic with ZW pair of Sex
chromosomes.

91. Male Female
ZZ ZW
Z Z Z W
ZZ ZZZW ZW
ZW = femaleZZ = Male
Parents-:
Phenotype
Genotype
Gametes
F1 Generation
Meiosis 
Mechanism of sex determination in Birds
Possibility of 50 % Male & 50% Female offspring

92. Female Bird
Male Bird
Z Z
Z
W
Z Z
Parent
Gametes
Z W
Z W
Z WZ Z Z Z
F1 Generation
Male birds ( 50% ) Female bird ( 50% )

93. 9

94. Mendelian Disorders Thalasemia
Sex
Chromosomal
Abnormalities
Turners
syndrome
Klinefelter’s
Syndrome
Autosomal
Chromosomes
Abnormalities
Patau’s syndrome
Down’s Syndrome
Edwards Syndrome

95. Thalassemia
In alpha thalassemia, the hemoglobin
does not produce enough alpha protein.
To make alpha-globin protein chains, we
need four genes, two on each chromosome 16.
We get two from each parent. If one or
more of these genes is missing, alpha
thalassemia will result.
Que-: Write a brief account on thalassemia?
Mendelian Disorders -:

96. Thalassemia
Thalassemia is an autosomal recessive
disorder caused due to defective gene located on
either chromosome 16 or chromosomes 11.
It is a quantitative abnormality of
polypeptide Globin chain synthesis.
Thalassemia occurs in two major types vizually
1) alpha thalassemia & 2) beta thalassemia.

97. Alpha Thalassemia
 The severity of thalassemia depends on how many genes
are faulty, or mutated.
One faulty gene: The patient has no symptoms. A healthy
person who has a child with symptoms of thalassemia is a
carrier. This type is known as alpha thalassemia minima.
Two faulty genes: The patient has mild anemia. It is
known as alpha thalassemia minor.
Three faulty genes: The patient has hemoglobin H
disease, a type of chronic anemia. They will need regular
blood transfusions throughout their life.

98. Four faulty genes: Alpha thalassemia major is the most
severe form of alpha thalassemia. It is known to cause
hydrops fetalis, a serious condition in which fluid
accumulates in parts of the fetus body.
A fetus with four mutated genes cannot produce
normal hemoglobin and is unlikely to survive, even with
blood transfusions.
Alpha thalassemia is common in southern China,
Southeast Asia, India, the Middle East, and Africa.
Alpha Thalassemia

99. Beta Thalassemia
We need two globin genes to make beta-globin chains, one
from each parent.
If one or both genes are faulty, beta thalassemia will occur.
Severity depends on how many genes are mutated.
One faulty gene: This is called beta thalassemia minor.
Two faulty genes: There may be moderate or severe
symptoms. This is known as thalassemia major. It used to
be called Colley's anemia.
Beta thalassemia is more common among people of Mediterranean
ancestry. Prevalence is higher in North Africa, West Asia, and the
Maldive Islands.

100. Symptoms
 The symptoms of thalassemia, vary vastly, depending on
the type of thalassemia.
 Symptoms will not show until the age of 6 months in most
infants with beta thalassemia and some types of alpha
thalassemia.
 This is because neonates have a different type of
hemoglobin, called fetal hemoglobin.
 After 6 months "normal" hemoglobin starts replacing the
fetal type, and symptoms may begin to appear.
Thalassemia

101. These include:
Thalassemia
Symptoms
 Jaundice and pale skin
 Drowsiness & fatigue
 Chest pain
 Cold hands and feet
 Shortness of breath
 leg cramps
 Rapid heart beat
 Poor feeding
 delayed growth
 Headaches
 Dizziness and faintness
 Greater susceptibility to
infections
Skeletal deformities may
result as the body tries to
produce more bone
marrow.

102. Treatments
Thalassemia
 Blood transfusions
 Iron chelation
 Bone marrow, or stem cell, transplant
 Surgery: This may be necessary to correct bone abnormalities.
 Gene therapy

103. 9

104. Down’s Syndrome
 The appeared different type of symptoms in patient is called
Syndrome.
 This syndrome was described by John Langdon Down.
 It is caused by aneuploidy which means addition or deletion
of one or two chromosomes in diploid chromosomes number.
 Down’s Syndrome is due to an extra chromosome number 21.
 It shows presence of three copies of 21st chromosomes
instead of homologous pairs.

105. Down’s Syndrome
 Such a genetic disorder is described
as triosomy for 21st chromosomes. It
is due to failure of separation of
chromosomes or non–disjunction
during meiosis.
 The occurrence of extra
chromosome in diploid chromosome is
called Triosomy. It is represented by
(2n+1).
What are the cause of
Down Syndrome?

106. Down’s Syndrome
Symptoms-:
1) Most children shows typical facial features with a fold of skin
over the inner corner of eye. This result in downward slanting of
eyelids.
2) The face is typically flat & rounded flat nose,
mouth open & tongue protruding.
Que-: What are the characteristics of Down’s Syndrome?

107. Down’s Syndrome
Symptoms-:
3) Mental retardation.
4) Due to poor skeletal development, they have short
stature & relatively small skull, palate is arched.
5) Flat hand with characteristics crease which runs all the
way across the palm.(Simian crease)

108. 9

109. Que-: What are the different type of chromosomal
aberration? Give suitable example?
 Chromosomal aberration are of two types viz.
1) Autosomal Aberration &
2) Sex Chromosomal aberration.
1) Autosomal Aberration-:
Down’s Syndrome (Triosomy of 21st Chromosomes),
Edword’s Syndrome (Triosomy of 18th chromosomes),
Patau’s Syndrome (Triosomy of 13th chromosomes)
2) Sex Chromosomal Aberration-:
Turner’s syndrome (44 + XO),
Klinefelter’s Syndrome(44 + XXY)

113. Write a brief account on Turner’s Syndrome?

115. Distinguish between Turners Syndrome & Klinfesters Syndrome?

116. Show the schematic representation of Cross A & Cross B performed by Morgans to study Linkage
& crossing over in Drosophila.?

117. Write a note on crossing over?

118. You did it very well.
Thank you…….
On the behalf of
Pacific Coaching Classes,
Ner parsopant
Mr. Abhay Ishwar Bhansali
B.Sc.(Evs), M.Sc.(Evs), B.Ed.
Cell no. +91 – 88888-21-956