When you visit a DDS Customer Service Center, you'll need: 1  your birth certificate, your current US passport or other proof of citizenship. 2  your Social Security Card or other verification of your Social Security Number.  two proofs of residence (recent utility bills, bank statements and rental contracts all work)
Crossing over begins early in prophase I of meiosis. At the time, homologous chromosomes Are paired along their lengths. Each gene on one homologue ia alined precisely with thâ¦e corresponding gene on the other homologue.
Crossing over, or recombination, is the exchange of chromosome segments between nonsister chromatids in meiosis. Crossing over creates new combinations of genes in the gametes that are not found in either parent, contributing to genetic diversity.