Crossing over and random segregation result in genetic recombination of paternal and maternal genes within each gamete. 2 different gametes unite during sexual reproduction, a further mixing of genetic material occurs and results in offspring with many new combinations of genes.
Variation caused by mutations— replication of dna or during separation of chromosomes(chromosomal mutations formed)
Replication errors in meiosis may arise in a similar manner to mitosis leading to point mutations
