How are chromosomes inherited?
The usual number of chromosomes in each cell of your body is 46 total chromosomes, or 23 pairs. You inherit half of your chromosomes (one member of each pair) from your biological mother, and the other half (the matching member of each pair) from your biological father. Scientists have numbered the chromosome pairs from 1 to 22, with the 23rd pair labeled as X’s or Y’s, depending on the structure. The first 22 pairs of chromosomes are called “autosomes.” The 23rd pair of chromosomes are known as the “sex chromosomes,” because they determine whether someone will be born male or female. Females have two “X” chromosomes, and males have one “X” and one “Y” chromosome. A picture of all 46 chromosomes, in their pairs, is called a karyotype. A normal female karyotype is written 46, XX, and a normal male karyotype is written 46, XY.
