Paper 2 · Inheritance and Variation
During prophase I of meiosis, non-sister chromatids of homologous chromosomes exchange equivalent lengths of DNA. Name this process.
Model answer
crossing over
Also accepted: crossing-over, crossover, cross over
Explanation: The exchange puts maternal alleles onto a paternal chromatid and the reverse, creating new linkage groups that neither parent carried. It is the second major source of variation in meiosis, alongside independent assortment.
Derived from ZIMSEC Biology Paper 2, Nov 2004, Q11