by kritika choudhary ppt on mutation description on types of mutation

2.  Changes in the nucleotide
sequence of DNA
 May occur in somatic cells
(aren’t passed to offspring)
 May occur in gametes
(eggs & sperm) and be
passed to offspring

3.  Mutations happen regularly
 Almost all mutations are
neutral
 Chemicals & UV radiation
cause mutations
 Many mutations are repaired
by enzymes

4.  Some type of skin cancers and
leukemia result from somatic
mutations
 Some mutations may improve
an organism’s survival
(beneficial)

5.  SPONTANEOUS MUTATION
 INDUCED MUTATION

6. SPONTANEOUS MUTATION
they are mainly caused
during dna replication or
by incorporation of
incorrect nucleotide in the
growing dna chain .
They occur naturally by
changes in DNA sequence
during replication.

7.  Induced mutation are caused
by the changes in DNA
brought about by some
environmental factor called
mutagens.
 E.g.- UV light,x-rays,gamma
rays etc…,

9.  May Involve:
› Changing the
structure of a
chromosome
› The loss or gain of
part of a
chromosome

10.  Five types exist:
› Deletion
› Inversion
› Translocation
› Nondisjunction
› Duplication

11.  Due to breakage
 A piece of a chromosome is lost

12.  Chromosome segment breaks
off
 Segment flips around
backwards
 Segment reattaches

13.  Occurs when a gene sequence
is repeated

14.  Involvestwo chromosomes that
aren’t homologous
 Partof one chromosome is
transferred to another
chromosomes

16.  Failure of chromosomes to separate during
meiosis
 Causes gamete to have too many or too few
chromosomes
 Disorders:
 Klinefelter’s Syndrome – XXY
chromosomes
› Down Syndrome – three 21st
chromosomes
› Turner Syndrome – single X chromosome

20.  Change in the nucleotide
sequence of a gene
 May only involve a single
nucleotide
 May be due to copying
errors, chemicals, viruses,
etc.

21.  Include:
› Point Mutations
› Substitutions
› Insertions
› Deletions
› Frameshift

22.  Change of a single
nucleotide
 Includesthe deletion,
insertion, or substitution of
ONE nucleotide in a gene

23.  Sickle Cell
disease is the
result of one
nucleotide
substitution
 Occurs in the
hemoglobin
gene

24.  Inserting
or deleting one or
more nucleotides
 Changes the “reading frame”
like changing a sentence
 Proteins built incorrectly

25.  Original:
The fat cat ate the wee rat.
 Frame Shift (“a” added):
› The fat caa tet hew eer at.

27.  This
type of mutations
generate a visible
morphological alterations.
 E.g-shape,colour,&size.

28.  They are fatal in nature
leading to the death of
individuals .

29.  Conditional mutations are normal
under one condition (permissive),
but abnormal under another
(restrictive).
 These are extremely useful for
studying processes such as
development and DNA replication.

30.  These mutations cause loss
or of some biochemical or
nutritional function in the cell.

34. 2n = 46 34

35. 2n = 46
35

36. 2n = 47
36

37. 2n = 47
37

38. 2n = 47
38

39. 2n = 45
39