Which processes during meiosis contribute to genetic variation in offspring?

• A. Crossing over and independent assortment
• B. Mitosis and cytokinesis
• C. DNA replication and transcription
• D. Protein synthesis

Answer: (A)

Genetic variation in offspring comes from two meiotic mechanisms that shuffle alleles: crossing over and independent assortment. Crossing over occurs in prophase I when homologous chromosomes pair up and exchange segments, producing chromatids with mixed maternal and paternal genes. Independent assortment happens in metaphase I and anaphase I as chromosome pairs line up and separate randomly, so gametes receive different combinations of maternal and paternal chromosomes. Together, these processes create the diverse genetic combinations that offspring inherit after fertilization.

Mitosis and cytokinesis are about cell division within body cells and don’t create new allele combinations. DNA replication and transcription are about copying DNA and making RNA, not generating new genetic mixes in gametes. Protein synthesis is translating RNA into proteins, not producing variation in offspring.