EXERCISE (mutation)

1. Mutation is a change which occur spontaneously in chromosome or gene.

2. Name two types of mutation

a) Chromosome mutation
b) Gene mutation

3. Identify the following disorders that caused by chromosome mutation:


a) A person who has three sex chromosome (XXY) instead of the usual two
sex chromosome (XY)
Klinefelter’s syndrome

b) A female who has only X chromosome (XO)
Turner’s syndrome

c) He/she has an extra chromosome 21. This person has 47 chromosomes
in somatic cell instead of the normal person.
Down’s syndrome

4. Gene mutation is due to chemical changes in individual gene.

5. List the consequences of gene mutation.

a) colour-blindness
b) albinism
c)haemophilia
d)thalasseamia

6. Complete the schematic diagram of colour-blindness below:

Keys: X : X chromosome which carries the normal gene
X : X chromosome which carries the recessive gene for colour-blindness


Parent : father X mother


Meiosis

Gametes:

Fertilization


Baby:

MUTATION

• Mutation is a change which occur spontaneously in chromosome or gene.


• There are two types of mutation; chromosome mutation and gene mutation


• Chromosome mutation refer to change in stucture or number of chromosome.
  
• The consequences of chromosome mutation includes Down's suyndrome, Klinefelter's syndrome and Turner's syndrome.

Down's syndrome

Turner's syndrome

• Gene mutations due to chemical changes in individual genes.
  
• The consequences of gene mutation are colour-blindness, haemophilia, albinism and thalasseamia. Albino
  
  
  Thalassaemia