Final answer:
Genetic recombination, crossing over, and random chromosome assortment are three events/processes that increase variation in offspring during sexual reproduction. These processes occur during fertilization and meiosis.
Step-by-step explanation:
The three events/processes that increase the variation in offspring during sexual reproduction are genetic recombination, crossing over, and random chromosome assortment.
The genetic recombination occurs during fertilization, where the genetic material from both parents combines to form a new unique individual.
Crossing over happens during meiosis, specifically in Prophase I, where segments of homologous chromosomes exchange genetic material, resulting in new combinations of genes.
Random chromosome assortment also occurs during meiosis, specifically in Metaphase I, where homologous pairs of chromosomes line up randomly, leading to the independent assortment and mixing of genes.