Crossing over, random orientation of chromosomes, and random fertilization are mechanisms involved in meiosis and sexual reproduction that generate diversity.

Sure, here's a step-by-step explanation of how these mechanisms generate diversity:

1. Crossing Over: This occurs during Prophase I of meiosis. Homologous chromosomes pair up and exchange segments of DNA. This means that the genes from the mother and father can mix, creating new combinations. This is one of the main sources of genetic variation in offspring.

2. Random Orientation of Chromosomes: This occurs during Metaphase I of meiosis. The way in which the homologous chromosomes line up along the metaphase plate is completely random and independent for each pair. This means that the combination of whether the daughter cells get the mother's or father's chromosome for each homologous pair is random. This random assortment leads to many possible combinations of chromosomes in the gametes, contributing to genetic diversity.

3. Random Fertilization: This is the process by which one sperm cell fertilizes one egg cell. Because each sperm and egg cell is genetically unique due to crossing over and random orientation, the fertilization process is random as well. This means that any sperm can fertilize any egg, leading to a huge number of possible genetic combinations in the offspring.

In conclusion, these three mechanisms involved in meiosis and sexual reproduction generate genetic diversity by creating new combinations of genes. This diversity is crucial for the survival and evolution of species.