Answer
During meiosis 1 paired homologous chromosomes become attached along their lengths. The points of attachment between ese bivalent chromosomes are called chiasmas or chiasmata. When the bivalents separate, portions of chromosomes ( genetic material) may be exchanged between non-sister chromatids): this is called crossing over and probably takes place a few times in each tetrad formation.
Recombinations add new genetic traits to each chromatid , and when these separate into haploid nuclei at anaphase 2-telophase, the new haploid cells will be different genetically from the parent cells.
Work Step by Step
The new genes formed by recombinations at crossing over are not found in parents or in parental generations ; this process of crossing over is thus an endless source of genetic variation which facilitates adaptation and survival
