The Causes of Variation and It's Biological Importance

731 Words3 Pages
The causes of variation and it’s biological importance Variation refers to the different characteristics that an individual possesses which are different from the others of the same kind. Variation can be interspecific, which are variation that exists between different species. Or it can be intraspecific; the variation that occur within a species. Although the individual of the same species may appear similar, no two individuals are exactly alike. Variation can be caused by genetic factors, environmental factors, or often both combined. For example: a person might have the genes to potentially grow to be six foot tall, however, whether or not they grow to this height will depend on environmental factors such as their diet and health. Although the members of a species have the same genes, individuals within that species can have different versions of those genes- called alleles. The alleles an organism has make up its genotype, different genotypes result in variation in the phenotype, and phenotype is the characteristics displayed by an organism. One of the causes that brought about the differences in alleles is sexual reproduction during meiosis. There are two main events during meiosis, crossing over of chromatids and independent segregation of chromosomes. During meiosis I, homologous pairs of chromosomes come together and pair up. The chromatids twist around each other and bits of chromatids swap over, the crossing over of chromatids in meiosis I means that each of the four daughter cells formed from meiosis II contain chromatids with a different set of alleles, which increases genetic variation. Meanwhile during the independent segregation of chromosomes, half of your chromosomes come from your mum (called maternal chromosomes) and half from your dad (called paternal chromosomes). When the gametes are produced, different combinations of those maternal and

More about The Causes of Variation and It's Biological Importance

Open Document