Like any other field in science, genetics has its own language. However, genetics is also a multidisciplinary field that encompasses expertise, and hence terminology, from diverse areas of science, including molecular biology, statistics, clinical medicine, and, most recently, bioinformatics. Despite all of the new and changing language in the field, two of the most frequently used terms in genetics are still "chromosomes" and "genes."

Humans have twenty-three pairs of chromosomes. One member of each pair is inherited from the person's mother, and the other from the father. Of the pairs, twenty-two are known as autosomes. The remaining pair consists of the sex chromosomes, which determine a person's gender. Females have two X chromosomes, and males have one X chromosome and one Y chromosome.

Chromosomes are located in the nucleus of a cell. During cell division, which is known as mitosis, the chromosomes' long strands coil up tightly, to...