Which process increases genetic variation by producing recombinant chromosomes during meiosis?

• A. Mitosis
• B. Crossing over
• C. Fertilization
• D. DNA replication

Answer: (B)

Genetic variation during meiosis increases when homologous chromosomes exchange genetic material in a process called crossing over. In prophase I, paired homologs physically swap segments, producing recombinant chromosomes that contain a mix of maternal and paternal alleles. This shuffling creates new allele combinations in the gametes, which boosts diversity among offspring. Other options don’t generate this kind recombination during meiosis: mitosis produces identical cells with no mixing of alleles, DNA replication only copies the genome without rearranging it, and fertilization increases variation by combining gametes but doesn’t produce recombinant chromosomes within a single meiotic event.