Mutations are changes in genetic material that can result from errors during DNA replication or damage to DNA. There are two main types of mutations: chromosomal mutations and genetic mutations. Chromosomal mutations include deletions, duplications, inversions, and translocations that involve changes in chromosome structure. Genetic mutations are changes in DNA sequence, such as point mutations involving substitutions, insertions, or deletions of nucleotide bases. Insertion and deletion mutations tend to have the largest effects as they can alter multiple amino acids and proteins, while substitution mutations often have the smallest effects since only a single amino acid may change. Examples of diseases caused by mutations include sickle cell anemia from a substitution and Huntington's disease from an expansion insertion.

1. Sickle Shaped Red Blood Cells
Prepared by: Gautam Kumbhani
Guided By: J S S Mohan sir
Roll No: 2 (M.Sc Biotechnology)

2. In biology, a mutation is the permanent alteration of
the nucleotide sequence of the genome of
an organism, virus, or extrachromosomal DNA or
other genetic elements.
Mutations result from errors during DNA
replication or other types of damage to DNA
Mutations play a part in both normal and abnormal
biological processes including: evolution, cancer, and
the development of the immune system,
including junctional diversity.

3. Mutations occurs at a frequency of about 1 in
every 1 billion base pairs
Everybody has about 6 mutations in each cell in
their body!

4. 1st
CHROMOSOMAL MUTATION
2nd
GENETICS MUTATION

5. There have four types:
1. Deletion
2. Duplication
3. Inversion
4. Translocation

6. Deletions reduce the amount of DNA of a
chromosome compared to the normal chromosome.
Small deletions are less harmful than large deletions.
The chromosomes with deletions can never revert to a
normal condition
If gametes arise from the cells having a deleted
chromosome, this deletion is transmitted to the next
generation.
Terminal deletion
Interstitial deletion

8. Duplications increase the amount of DNA of a
chromosome compared to the normal
chromosome.
Thus, due to duplication some genes are present
in a cell in more than two doses
The presence of a part of a chromosome in excess
of the normal complement is known as
duplication

9. Schematic of a
region of a
chromosome before
and after a
duplication event

10. Inversion involves a rotation of a part of a chromosome
or a set of genes by 180* on its own axis
It essentially involves occurrence of breakage and
reunion
The net result of inversion is neither a gain nor a loss in
the genetic material but simply a rearrangement of the
gene sequence
An inversion can occur in the following way : suppose
that the normal order of segments within a
chromosome is 1-2-3-4-5-6 ; breaks occur in regions 2-3
and 5-6 and broken piece is reinserted in reverse order.
This results in an inverted chromosome having
segments 1-2-5-4-3-6

11. There two types:
1. Paracentric inversion
2. Pericentric inversion

12. The shifting or transfer of a part of a chromosome or a
set of genes to a non-homologous one, is called
translocation
There is no addition or loss of genes during
translocations, only a rearrangement
Translocations may be of following three types
1. Simple translocations.
They involve a single break in a chromosome.
The broken piece gets attached to one end of a
nonhomologous chromosome.

13. 2. Shift translocation.
 In this type of translocation, the broken segment of
one chromosome
gets inserted interstitially in a nonhomologous
chromosome.
3. Reciprocal translocations.
 In this case, a segment from one chromosome is
exchanged with
a segment from another nonhomologous one, so that
in reality two translocation chromosomes are
simultaneously achieved.

15. 2. Genetic Mutation

16. Mutations are changes in genetic material –
changes in DNA code – thus a change in a
gene(s)
In gene mutations, the DNA code will have a
base (or more) missing, added, or exchanged in a
codon.

17.  Point mutation occurs when the base
sequence of a codon is changed. (ex.
GCA is changed to GAA)
 There are 3 types:
Also called
frameshift
mutations
•Substitution
•Deletion
•Insertion

18. What will happen to
the amino acids?
Normal DNA: CGA – TGC – ATC
Mutated DNA: CGA – TGC – TTC
Alanine – Threonine - stop
Alanine – Threonine - Lysine
This is a substitution
mutation
The adenine was
replaced with thymine
What has happened to
the DNA?

19. This is a substitution mutation.
A single nitrogen base is substituted for another
in a codon.
It may or may not affect the amino acid or protein.
Mutated DNA: CGA – TGC – TTC
Alanine – Threonine - Lysine
Normal DNA: CGA – TGC – ATC
Alanine – Threonine - stop

20. This is an insertion
mutation, also a type of
frameshift mutation.
Normal DNA: CGA – TGC – ATC
Mutated DNA: CGA – TAG – CAT – C
Alanine – Threonine – stop
Alanine – Isoleucine – Valine
What will happen to the
amino acids?
An adenine was inserted
thereby pushing all the
other bases over a frame.
What has happened
to the DNA?

21. This is an insertion mutation.
A nitrogen base is inserted/added to the sequence.
It causes the triplet “frames” to shift.
It always affects the amino acids and, consequently,
the protein.
Mutated DNA: CGA – TAG – CAT – C
Alanine – Leucine - Valine
Normal DNA: CGA – TGC – ATC
Alanine – Threonine - stop

22. What will happen to the
amino acids?
Mutated DNA: CGA – TCA- TC
A guanine was deleted,
thereby pushing all the
bases down a frame.
Alanine – Threonine – stop
Alanine – Serine
Normal DNA: CGA – TGC – ATC
This is called a deletion
mutation, also a type of
frameshift mutation.
What has happened
to the DNA?

23. This is a deletion mutation.
A nitrogen base is deleted/removed from the
sequence.
It causes the triplet “frames” to shift.
It always affects the amino acids and, consequently,
the protein.
Mutated DNA: CGA – TCA- TC
Alanine – Threonine – stop
Alanine – Serine
Normal DNA: CGA – TGC – ATC

24. Which mutation would have the least affect
on an organism?
Substitution has the least affect because
it changes only one amino acid or it may
change no amino acid.
Mutated DNA: CGA – TGC – ATT
Alanine – Threonine - stop
Normal DNA: CGA – TGC – ATC
Alanine – Threonine - stop
Mutated DNA: CGA – TGC – ATG
Alanine – Threonine - Tyrosine

25. An example of a substitution mutation is
sickle cell anemia.
Only one amino acid changes
in the hemoglobin.
The hemoglobin still
functions but it folds
differently changing the
shape of the rbc.
Sickle Shaped Red Blood Cells
Normal Red Blood Cells

27. Which mutation would have the most affect
on an organism?
Insertion and deletion mutations have the
most effect on an organism because they affect
many amino acids and consequently the whole
protein.
Mutated DNA: CGA – TCA- TC
Alanine – Threonine – stop
Alanine – Serine
Normal DNA: CGA – TGC – ATC
Mutated DNA: CGA – TAG – CAT – C
Alanine – Leucine - Valine

28. Huntington’s Disease is caused by an
insertion mutation.
People with this disorder
have involuntary
movement and loss of
motor control. They
eventually have memory
loss and dementia. The
disease is terminal.
Huntington Disease
Located on chromosome 4
First Gene Disease Mapped

30. Can't be cured, but treatment may help
Requires a medical diagnosis
Lab tests or imaging always required
Chronic: can last for years or be lifelong
It typically starts in a person's 30s or 40s.
Usually, Huntington's disease results in
progressive movement, thinking
(cognitive) and psychiatric symptoms.

31. What causes mutations?
natural errors or an environmental event
What is a mutagen?
something that causes the DNA code to change
(mutate) – x-ray, chemicals, UV light, radiation,
etc
What happens to a person who has a mutation?

32. Pierce of genetics – Benjamin A. Pierce
Additional information of source of
internet

33. THANK YOU