(A) No crossing-over (B) Crossing-over Chiasma ossing-over betwe these chromatids Nonrecombinant Recombinant chromatids Result: Four Result: Two recombinant nonrecombinant and two nonrecombinant chromatids chromatids 图5-6交换与重组烈配子形成过程的示意图图5－6 交换与重组型配子形成过程的示意图