The pairing of chromosomes along their lengths which is essential for crossing over is referred to as Naim 21:21 Heredity Meiosis Molecular Genetics The pairing of chromosomes along their lengths which is essential for crossing over is referred to as a. syngamy. b. synapsis. c. prophase. d. recombination. e. entromere. Answer: B Learn More : Share this Share on FacebookTweet on TwitterPlus on Google+