Homologous chromosomes are two chromosomes of the same length and mitotic position seen in mid mitosis, or two pairs of chromosomes seen in meiosis. Homologous chromosomes are chromosomes of essentially the same shape and structure in the cells of diploid organisms that are linked to each other at the tetrad stage of the first meiotic division. In the case of triploid and other odd-ploid biological cells, this linkage is disorganized and eventually divides into different germ cells, i.e., sperm and egg cells are pairs of chromosomes, one from the mother and the other from the father. Thus, two sex cells formed from a single sex mother cell are identical. Usually there are only two types of sex cells and the segregation of homologous chromosomes occurs during the first meiotic division. Furthermore, homologous chromosomes are a concept in biogenetics. Whether it is animals or plants, different species have chromosomal differences to distinguish between species and different genes.