Which process results in genetic variation by exchanging genetic information between homologous chromosomes?

Which process results in genetic variation by exchanging genetic information between homologous chromosomes?

• A. Crossing over
• B. Independent assortment
• C. Cytokinesis
• D. Synapsis

Answer: (A)

Crossing over is the process that exchanges genetic information between homologous chromosomes during meiosis, producing new allele combinations. During prophase I, homologous chromosomes pair up tightly in a stage called synapsis to form a tetrad. Within this pairing, non-sister chromatids touch at points called chiasmata and swap equivalent segments. This reciprocal exchange creates chromatids that carry mixes of maternal and paternal alleles, increasing genetic diversity in the gametes. Independent assortment also contributes to variation, but it does so by the random orientation of chromosome pairs during cell division, not by exchanging genetic material itself. Cytokinesis is the physical separation of the cytoplasm to form two cells and does not alter the genetic content. Synapsis is the pairing process that aligns homologous chromosomes to enable crossing over, but the actual genetic exchange happens during crossing over itself.

Crossing over is the process that exchanges genetic information between homologous chromosomes during meiosis, producing new allele combinations. During prophase I, homologous chromosomes pair up tightly in a stage called synapsis to form a tetrad. Within this pairing, non-sister chromatids touch at points called chiasmata and swap equivalent segments. This reciprocal exchange creates chromatids that carry mixes of maternal and paternal alleles, increasing genetic diversity in the gametes.

Independent assortment also contributes to variation, but it does so by the random orientation of chromosome pairs during cell division, not by exchanging genetic material itself. Cytokinesis is the physical separation of the cytoplasm to form two cells and does not alter the genetic content. Synapsis is the pairing process that aligns homologous chromosomes to enable crossing over, but the actual genetic exchange happens during crossing over itself.