Summary:
- Crossing-over is the exchange of genetic material between homologous chromosomes.
- It results in new combinations of genes on each chromosome.
- Sexual reproduction results in offspring that are genetically unique.
- Each human couple has the potential to produce more than 64 trillion genetically unique children.
- Together with random fertilization, more possibilities for genetic variation exist between any two people than the number of individuals alive today.
- In humans, over 8 million (223) chromosome combinations exist in the production of gametes in both the male and female.