Two homologous chromosomes (maternal and paternal) are paired in a synaptonemal complex; non-sister chromatids overlap at a chiasma where DNA is exchanged.
Which best describes the genetic outcome of the event diagrammed?
- Acheck_circle
Recombinant chromatids carry new combinations of maternal and paternal alleles.
- B
Sister chromatids exchange identical DNA, producing no genetic change.
- C
Centromeres are duplicated, doubling chromosome number.
- D
The cell becomes polyploid as a result of unequal crossover.
Explanation
Crossing over at the chiasma swaps homologous (non-sister) chromatid segments, producing recombinant chromatids that combine alleles from both parents and increasing genetic diversity.