DNA
DNA, which stands for deoxyribonucleic acid, is a chemical substance found in the cells of all living organisms. It is made up of four different molecules—adenine (A), thymine (T), cytosine (C), and guanine (G)—that are arranged in meaningful sequences. These sequences provide the code for our physical attributes and instructions for our bodies’ functions. This is why DNA is commonly known as the blueprint for the body.
DNA is the basis of heredity. At conception, a zygote is formed from the mother’s egg cell (carrying one-half of the mother’s DNA) and the father’s sperm cell (carrying one-half of the father’s DNA). The resulting child receives a unique combination of his or her biological parents’ DNA.
Because a child receives half of his or her DNA from each biological parent, two individuals’ genetic profiles can be analyzed and compared to determine whether they are biologically related as parent and child. A biologically related parent and child will share at least half of the same DNA markers. This is the basis of parentage testing, such as paternity and maternity testing.
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