Crossing over, or recombination, occurs in the early stages of meiosis, when the homologous pairs of replicated chromosomes are in close proximity. In most cases, crossing over is beneficial because it increases genetic variation in offspring.
4.2 Meiosis
Prophase, Definition, Mitosis, Summary, & Facts
Tetrad, chromosome
Meiosis - Wikipedia
Crossing Over in Meiosis, Overview & Examples - Lesson
cell - Students, Britannica Kids
Crossing Over and Nondisjunction Diagram Activities by Science With Mrs Lau
Meiosis, Definition, Process, Stages, & Diagram
Crossing over - Simple English Wikipedia, the free encyclopedia
gamete formation in meiosis - Students