Mutations are changes in the nucleotide sequence of DNA that may occur in somatic or gamete cells. Most mutations are neutral or harmful, causing diseases like cancer, but some may provide benefits like improved survival. There are two classes of mutation: spontaneous mutations, which naturally occur during DNA replication, and induced mutations caused by mutagens like UV light and radiation. Different types of mutations include chromosome mutations like deletions or inversions, as well as morphological, lethal, conditional, and biochemical mutations.

1. MUTATIONS
BY: MRS. PRECILLA C. STEPHEN

2. WHAT ARE MUTATIONS?
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. ARE MUTATIONS HELPFUL OR HARMFUL?
 Mutations happen regularly
 Almost all mutations are neutral
 Chemicals & UV radiation cause mutations
 Many mutations are required by enzymes

4. ARE MUTATIONS HELPFUL OR HARMFU?
 Some type of skin cancers and Leukemia result from somatic
mutations
 Some mutations may improve an organisms survival (beneficial)

5. CLASSES OF MUTATION
 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
 Induced mutation are caused by the changes in DNA brought about by
some environment factor called mutagens.
 Ex: UV lights, X-Rays, gamma rays etc.

8. TYPES OF MUTATIONS

9. CHROMOSOMES MUTATIONS
 May involve:
 Changing the structure of a chromosome.
 The loss or gain of part of a chromosome.

10. CHROMOSOME MUTATIONS
Deletion
Inversion
Translocation
Nondisjunction
Duplication

24. MORPHOLOGICAL MUTANTS
This type of mutations generate a visible morphological
alterations.
Ex: Shape, color & Size.

25. LETHAL MUTANTS
 They are fatal in nature leading to the death of individuals.

26. CONDITIONAL MUTANTS
Conditional mutations are normal under one
condition but abnormal under another.
These are extremely useful for studying processes
such as development and DNA replication.

27. BIOCHEMICAL MUTATIONS
These mutation cause loss or of some biochemical or
nutritional function in the cell.