Final answer:
Crossing over, independent assortment, and random fertilization are processes that lead to genetic variation in offspring.
Step-by-step explanation:
Crossing over, independent assortment, and random fertilization are all processes that lead to genetic variation in offspring.
Crossing over occurs during meiosis when homologous chromosomes exchange genetic material, resulting in new combinations of alleles on the chromosomes.
Independent assortment is the random alignment of homologous pairs of chromosomes during metaphase I of meiosis, which leads to different combinations of chromosomes in each gamete.
Random fertilization occurs when any sperm can fertilize any egg, resulting in different combinations of genes from the parents in each offspring.