Final answer:
Synapsis during meiosis is crucial for pairing homologous chromosomes, facilitating crossing over, and promoting genetic variation by exchanging DNA segments between non-sister chromatids.
Step-by-step explanation:
The point of synapsis in meiosis is to allow homologous chromosomes to pair up precisely, enabling the exchange of genetic material through a process known as crossing over. This genetic recombination contributes to the genetic diversity of offspring. Synapsis occurs during prophase I of meiosis, where homologous chromosomes come together and are held tightly by the synaptonemal complex and cohesin proteins at the centromere. It's during this alignment that crossing over can occur, wherein non-sister chromatids exchange DNA segments, leading to varied combinations of alleles. The recombination nodules on the synaptonemal complex indicate the sites of these crossover events. As the synaptonemal complex disassembles, the homologous chromosomes begin to separate, though they still remain connected at crossover points called chiasmata, ensuring proper chromosome segregation.