Final answer:
Intrachromosomal recombination occurs during prophase I of meiosis. This is when homologous chromosomes exchange segments of genetic material, resulting in increased genetic variation.
Step-by-step explanation:
Intrachromosomal recombination, or recombination between genes on the same chromosome, occurs during prophase I of meiosis. This is when homologous chromosomes line up in pairs, known as tetrads, and exchange segments of genetic material through a process called crossing over. This genetic recombination between chromosomes results in new allelic combinations and increases genetic variation in the offspring.