I'm not sure this is actually important to know for the MCAT because it might be a little too much detail for DNA replication, but, in all the books that I've read specifically made for the MCAT, none of them talk about the trombone model for dna replication. Most of them show one pol working upward on the leading strand and the other pol working downward in a ratcheting fashion on the lagging strand. But I was taught the trombone model in bio class in which the two pols are connected at the fork and the lagging strand is looped around to reverse the polarity and then the lagging strand itself is ratcheted through the replisome. Again, maybe this is too detailed for the MCAT itself but I haven't seen this model in any of the books that I've seen and it sort of bothers me.