Download - MUTATION.pptx chapter 3 science form 4
MUTATION
Meaning of mutationA change in the genetic information of an idividual
TYPES OF MUTATIONThere are two type of mutationa) Chromosome mutationb)Gene mutation
Chromosome mutationThe changes in the structure or number of
chromosomeExample: a) Down’s syndrome( extra
chromosome 21)b) Klinerfelter’s syndrome (XXY)c) Turner’s syndrome (XO)
Down’s syndromeCaused by the possession of an extra
chromosome 21 (47 chromosome)The characteristic- distorted of the brain
(terencat akal)
Klinerfelter’s SyndromeCaused by the presence of three sex
chromosome (XXY)Characteristic- a) are males with some female
characteristics (breast development)
b) small testes and sterile
Turner’s Syndrome A female who has only one X chromosome
(XO)Characteristic- a) has no ovaries
b) fails to develop normal secondary sexual characteristics
c) short d) has folds of skin on her
neck
Turner’s Syndrome
Gene mutationThe chemical changes in individual
genesExample: a) colour blindness
b) albinism
Colour blindnessThe inability of a person to differentiate
colours (green and red)
Albinism A gene mutation occurs that interfere with
melanin productionCharacteristic: a) Has light coloured skin,
‘pink’ eyes and white hair.
The caused of mutationsRadioactive gamma raysUltra violet lightX-rayChemicals(mustard gas)Chemicals substances
Chemical mutagen
Physical mutagen
MUTAGENS
Advantages and disadvantages of mutationCaused deformities or genetic
diseases(haemophilia and colour blindness)Increase the variationBetter change to survive