Question

What are sources for genetic variation?

Answer 1

Crossing over and mutations are the main sources of genetic variation.

Explanation:

Crossing over occurs when homologous chromosomes line up and exchange DNA with each other. In this case, the order of the nucleotides are changed, so genetic variation arises.

Mutations can also occur during DNA replication when DNA polyermase pairs a wrong nucleotide with the parent strand. If this mutation proves to be beneficial, then that organism is more likely to pass on this new trait, changing the gene pool and adding to genetic variation.