| Term | Definition |
| somatic cells | two homologous chromosomes consist of two identical sister chromatids joined at the centromere; diploid |
| gamete | has a single set of chromosomes; haploid |
| n=23 | haploid number in humans |
| 2n=46 | diploid number in humans |
| karyotype | display of micrographs of metaphase chromosomes of a cell, arranged by size and labeled in increasing numbers |
| homologous pairs | two chromosomes that make up a matched pair in a diploid cell; same length and centromere position; posses alleles for the same genes at corresponding loci; one homologous chromosome is inherited from the father and one from the mother |
| autosome | a chromosome not directly involved in determing the sex of an organism; in mammals, any chromosome other than X or Y |
| sex chromosome | determines whether an individual is male or female |
| XX | female sex chromosome |
| XY | male sex chromosome |