What types of DNA are in the human body

There may be multiple variants of any given gene in the human population (genes), leading to polymorphism. Many genes are not polymorphic, meaning that only a single allele is present in the population: the gene is then said to be fixed.[1] On average, in terms of DNA sequence all humans are 99.5% similar to any other humans.[2][3]

No two humans are genetically identical. Even monozygotic twins, who develop from one zygote, have infrequent genetic differences due to mutations occurring during development and gene copy-number variation.[4] Differences between individuals, even closely related individuals, are the key to techniques such as genetic fingerprinting. Alleles occur at diff