1) Chromosomes carry genetic information and are composed of DNA wrapped around proteins. They can be seen during cell division to consist of two parallel strands called chromatids connected at the centromere. 2) In human cells, there are normally 46 chromosomes in 23 pairs, with 22 matching pairs of autosomes and either two X chromosomes or an X and a Y chromosome. Chromosomes are grouped by size from A to G. 3) Chromosomal abnormalities can be numerical, involving the number of chromosomes, or structural, involving changes in chromosome structure like deletions, duplications, inversions, or translocations. These abnormalities often cause health problems.

1. Name:GADHAVI BHAGIRATH MANUBHAI
ROLL No : 740
Sem : 5
TOPIC : chromosomal mutation

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• Human Chromosome
• Chromosomes carries genetic
information.
• Composed of
deoxyribonucleic(DNA) acid on
framework of protein.
• Segment of DNA molecules
comprise the genes; units of
heredity.

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CHROMOSOMES
• During cell division the
chromosome can be
seen to consist of two
parallel strands: the
chromatids, held
together at one point
the centromere.

4. • It is the set of chromosomes of an individual.
• It is the systematized arrangement of the
chromosomes of a single cell.
• In the human cell, there are 46
chromosomes or 23 pairs (diploid number);
of these 23 pairs, 22 are similar in both sexes
and are called the autosomes. The
remaining pair is called sex chromosomes :
XX in the female cells and XY in the male
cells .
• Chromosomes are arranged in groups A to G
according to their shape & size.
Karyotype

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• Chromosomal Abnormalities
• Chromosomal abnormalities are either
numerical or structural.
• They are a very common cause of
early spontaneous miscarriage.
• Usually, but not always, cause
multiple congenital anomalies and
learning difficulties.

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Chromosomal Aberration
• STRUCTURAL ABERRATION
✓ Deletion
✓ Duplication
✓ Inversion
✓ Translocation
• Numerical Aberration
✓ Polyploidy: Multiple of the haploid
✓ Aneuploidy: Abnormal number

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Deletion : Loss portion of a
chromosome.
• Deletion Causative Agents: Heat, radiation,
viruses, chemicals, errors in recombination.
Result in partial monosomy,
• the organism is monosomic for the portion of
the chromosome that is deleted,
• as in monosomy, most segmental deletions are
deleterious.

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Cri-du-chat Syndrome
• Mental retardation
• Slow motor skill development
• Low birth weight and slow
growth
• Small head (microcephaly)
• Partial webbing of fingers or
toes
• wide-set eyes (hypertelorism)
• High-pitched cry

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Duplicate
• An event that results in
the increase in the
number of copies of a
particular chromosomal
region.

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Duplication
Causes:
-duplication often result from anequal
crossing over,
-can occur errors via replication during s
phase
Effect:
-results in gene redundancy,
-produces phenotypic variation,
-may provide an important source for
genetic variability during evolution

14. Chromosomal inversion
• Aberration in which a portion of the
chromosome is turned around 180°

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• The process of inversion
does not remove the gene,
but a specific piece of
chromosome breaks down
at a specific location and
reverses on another
chromosome.
• Hence the
rearrangement of the
original gene is seen
here

16. Translocation
• In translocation, a
chromosomal chamber is
exchanged between two
chromosomes
• Evolution plays an
important role in this
process, whether the two
chromosomes are identical
or heterogeneous.

17. Terminal Translocation

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Reciprocal Translocation

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Change in the number
of Chromosome
PLOIDY
• Euploidy • Aneuploidy
1. Monoploidy
2. Diplody
3. Polyploidy
1. Hyperploody
I) Trisomy
II) Tetrasomy
III) Polysomy
2. Hypoploidy
I) Menosomy
II) Nullisomy

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Euploidy
• Euploidy associated with
changes in the number of
sets of chromosomes
(n×1,2,3,4,....)
1.Haploidy (n×1)
(monoploidy)
2. Diplody (n×2)
3. Polyploidy
(n×3,4,5....)

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•Aneuploidy
(2n±1,2,3,4,....)
• In a Aneuploidy
one or more sets
of chromosomes
are found more or
less.

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i) Hyperploidy
(2n+1,2,3,...)
1.Trisomy
(2n+1)
2.Tetrasomy
(2n+2)
3. Polysomy
(2n+3,4,5,...)

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ii) Hypoploidy
(2n-1,2,3...)
1. Monosomy
(2n-1)
2. Nullisomy
(2n-2)

24. Thanks!
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