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DNA Consulting |
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What is DNA?
Deoxyribonucleic Acid, or DNA, is a long, filamentous molecule that is found in the cells of all living organisms. The function of DNA is to transmit information from generation to generation.
DNA is composed of four building blocks (nucleotides) which are designated by the letters A (adenine) T (thymine) G (guanine) and C (cytosine). Information is encoded by the sequence of the A, T, G and C bases, much as the sequence of letters make up words, sentences, paragraphs and books.
Every sperm and egg cell contains approximately 3 billion nucleotides! This quantity of human DNA is called a genome. When an egg and sperm fuse at conception, all of the resulting cells in the new individual (except red blood cells) contain two genomes.
DNA from two individuals will be similar, but not identical. However, each cell of an individual contains identical DNA.
A locus (pl. loci) is the location or name of a particular region of DNA within the genome.
A DNA profile will contain two alleles (types), one of maternal and one of paternal origin. If the two alleles are identical, the locus is homozygous. If the alleles are different, the locus is heterozygous.