BIOLOGY FORM 5: CHAPTER 6 – VARIATION Variation is the differences in characteristic between individuals in from the same species. There are two types of variation; continuous variation and discontinuous variation. Continuous variation does not have any distinct differences while discontinuous variation

has distinct differences.

Variation are caused by genetic factors and environmrntal factors. Variation caused by genetic factors include genetic recombination and mutation. Genetic recombination is a result of crossing over during prophase I of meiosis.

Independent assortment of homologous chromosomes to produce gametes with a number of combinations of chromosomes.

  Mutation is a sudden spontaneous change in the structure of genes or chromosomes. Mutation in humans can cause genetic disorder, deformity and even death. Mutation is caused by mutagen such as X- rays, radioactive rays,, ultraviolet light,

pesticide and cigarette smoke. A characteristic is controlled by genes. However, a genetic factor can interact with an

environmental factor to change the characteristic and causes variation.

Variation is important for the survival of a species because it enables the organism to survive in a changing environment.

We should accept that everyone is unique and respect their characteristics.