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