The document discusses different types of mutations that can occur in DNA, including changes in the nucleotide sequence that may happen in somatic or germ cells. Mutations can be caused spontaneously during DNA replication or DNA damage from environmental factors like UV radiation. Types of mutations include point mutations, deletions, inversions, translocations, duplications, and aneuploidy. These genetic changes can have varying effects from being neutral to causing genetic disorders or cancer.

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