Final answer:
During prophase I of meiosis I, homologous chromosomes undergo crossing-over, exchanging segments of genetic material, which leads to the formation of new allele combinations that increase genetic diversity.
Step-by-step explanation:
Exchange of Genetic Information in Meiosis
The step in meiosis where homologous chromosomes exchange genetic information is known as crossing-over. This process occurs during prophase I of meiosis I, when homologous chromosomes align with each other. During crossing-over, DNA segments are swapped between the paired chromosomes, leading to new combinations of alleles on each chromosome. This genetic recombination is essential for increasing genetic diversity and ensures that offspring inherit a mix of alleles from both parents. Recombination is a crucial event that affects the genetic makeup of gametes, and by extension, future generations.
In this phase, homologous chromosomes pair up closely, allowing like genes to align accurately. This alignment is the precursor to the exchange of genetic material, which can occur at multiple points along the chromosome. After crossing-over, the chromosomes contain a blend of maternal and paternal alleles, contributing to the genetic uniqueness of each individual. Moreover, the metaphase I stage also plays a significant role in ensuring the gametes receive a combination of chromosomes from both the mother and the father, asserting the importance of meiosis in producing genetically variable gametes for sexual reproduction.