3. INTRODUCTION:-
• Genetics damage is an abnormal chemical structure in DNA .The
agents which are caused for DNA damage called Mutagens.The
process is called mutation.It change the sequence of base pairs.
• It’s caused change in genetics material due to DNA damage the
base pair sequences are change and produced different
proteins.DNA damage prevent the replication mechanism.
• DNA damage caused by endogenous source of DNA damage
include hydrolysis, oxidation,alkylation and mismatch of DNA
base. It include ionizing radiation, Ultraviolet, Various chemical
agents.
5. Chromosomal Alternation
• Deletion – Loss of one or more nucleotides from a segment of DNA .Loss of
nucleotides base pairs from chromosome.ex-:Digeorge syndrome (Chromosome
no.22)
• Duplication - Adding 2copies of DNA sequence. Ex-:Pallister Killian
(Chromosome no.12)
• Inversion –Segment breaks off and reattached in same DNA but in reverse
sequence.DNA may or may not loss but the expression of gene will be change .
• Translocation – Piece of one chromosome segment breaks off and attached
onather chromosome.Ex- Down syndrome.
7. Chemical compounds causing DNA
damage -:
• DNA damageing agents are Classed are Carsinogens.
• DNA damage can arises from Exposure to Exogenous agent but damage from
endogenous process is probably far more .
• DNA damage induced by the following carcinogens: polycyclic aromatic hydrocarbons,
heterocyclic aromatic amines, mycotoxins, ultraviolet light, ionising radiation,
aristolochic acid, nitrosamines and particulate matter.
Fig 2-: The pathway of DNA damage And repair
8. REFERENCES:
-Smith M.T., Guyton K.Z., Gibbons C.F., Fritz J.M., Portier C.J.,
Rusyn I. et al. (2016) Key characteristics of carcinogens as a basis
for organizing data on mechanisms of carcinogenesis. Environ.
Health Perspect. 124, 713–721 10.1289/ehp.1509912 [PMC free
article] [PubMed] [CrossRef] [Google Scholar
9. ACKNOWLEDGEMENT
• Special thanks to my subject teacher Dr.Gagan
Kumar Panigrahi School of Applied Sciences
CUTM, Bhubaneswar.
• All the faculty of members of Department of
Zoology, School of Applied Sciences,CUTM,
Bhubaneswar.
• Family and friends.